Shrekpad

Wait for new CPUs and GPUs, you’re friend will get a lot more value for that price then.

Waiting is the best option right now, as new CPUs and GPUs are right around the corner. But if you need to buy parts soon then this is my advice:
You can get a 3600mhz CL16 ram kit for less, and should be better. I would expect a NVME ssd at that price like the Crucial P1. Also a 2080 super is overkill for 1080p gaming. Otherwise looks good.
 
PCPartPicker Part List Type Item Price CPU AMD Ryzen 7 3700X 3.6 GHz 8-Core Processor $283.55 @ B&H Motherboard Asus TUF GAMING X570-PLUS (WI-FI) ATX AM4 Motherboard $189.99 @ B&H Memory G.Skill Ripjaws V 16 GB (2 x 8 GB) DDR4-3600 CL16 Memory $76.99 @ Newegg Storage Crucial P1 1 TB M.2-2280 NVME Solid State Drive $102.99 @ Amazon Video Card Zotac GeForce RTX 2080 SUPER 8 GB GAMING Video Card $729.99 @ B&H Case Lian Li PC-O11 Dynamic Razer ATX Full Tower Case $169.99 @ B&H Power Supply Thermaltake Toughpower Grand RGB 750 W 80+ Gold Certified Fully Modular ATX Power Supply $117.23 @ B&H Monitor Samsung C27JG56 27.0" 2560x1440 144 Hz Monitor $279.99 @ Walmart   Prices include shipping, taxes, rebates, and discounts     Total $1950.72   Generated by PCPartPicker 2020-08-07 21:34 EDT-0400    

PCPartPicker Part List Type Item Price CPU AMD Ryzen 5 3600 3.6 GHz 6-Core Processor £159.99 @ AWD-IT Motherboard MSI B450M PRO-M2 MAX Micro ATX AM4 Motherboard £62.29 @ CCL Computers Memory Corsair Vengeance LPX 16 GB (2 x 8 GB) DDR4-3200 CL16 Memory £59.99 @ Amazon UK Storage Crucial P1 500 GB M.2-2280 NVME Solid State Drive £58.08 @ CCL Computers Video Card Asus Radeon RX 5700 XT 8 GB TUF Gaming X3 OC Video Card £330.48 @ Amazon UK Case Corsair SPEC-05 ATX Mid Tower Case £35.18 @ Amazon UK Power Supply Corsair TXM Gold 650 W 80+ Gold Certified Semi-modular ATX Power Supply £79.99 @ Currys PC World Monitor ViewSonic XG2405 23.8" 1920x1080 144 Hz Monitor £179.99 @ Box Limited Keyboard Logitech K120 Wired Standard Keyboard £13.41 @ BT Shop   Prices include shipping, taxes, rebates, and discounts     Total £979.40   Generated by PCPartPicker 2020-07-30 23:20 BST+0100   This is what I would recommend at this price point. The 3600 and any B450 MSI MAX will perform well. There are cheaper ssds than the 970 evo (like the Crucial P1) which are still good. I switched the 2070 out for a 5700 XT since it’s cheaper while still giving similar if not better performance, and it should be fine unless you wanted Raytracing, NVENC, or DLSS 2.0. I would get a better power supply than that, like the TXM 650 which for £30 more is much better. Otherwise everything else looks good.

This is what I would recommend:
PCPartPicker Part List Type Item Price CPU AMD Ryzen 5 3600 3.6 GHz 6-Core Processor $264.00 @ Newegg Australia Motherboard MSI B450M-A PRO MAX Micro ATX AM4 Motherboard $116.00 @ Skycomp Technology Memory G.Skill Aegis 16 GB (2 x 8 GB) DDR4-3200 CL16 Memory $95.70 @ Newegg Australia Storage Samsung 860 QVO 1 TB 2.5" Solid State Drive $149.00 @ Centre Com Video Card XFX Radeon RX 5700 XT 8 GB Triple Dissipation Video Card $620.40 @ Newegg Australia Case Thermaltake Versa H18 MicroATX Mini Tower Case $58.00 @ PC Byte Power Supply Cooler Master MasterWatt 550 W 80+ Bronze Certified Semi-modular ATX Power Supply $99.00 @ PC Byte Case Fan Cooler Master MF120R ARGB 59 CFM 120 mm Fans 3-Pack $65.00 @ Amazon Australia   Prices include shipping, taxes, rebates, and discounts     Total $1467.10   Generated by PCPartPicker 2020-07-26 07:43 AEST+1000    

here is what you could do:
PCPartPicker Part List Type Item Price CPU AMD Ryzen 5 3600 3.6 GHz 6-Core Processor £173.96 @ Amazon UK Motherboard MSI B550M PRO-VDH WIFI Micro ATX AM4 Motherboard £109.98 @ CCL Computers Memory Crucial Ballistix 16 GB (2 x 8 GB) DDR4-3600 CL16 Memory £68.39 @ Amazon UK Storage Kingston A2000 1 TB M.2-2280 NVME Solid State Drive £96.97 @ CCL Computers Video Card Gigabyte GeForce RTX 2060 SUPER 8 GB WINDFORCE OC Video Card £369.98 @ Scan.co.uk Case Corsair 275R Airflow ATX Mid Tower Case £67.92 @ More Computers Power Supply Corsair TXM Gold 650 W 80+ Gold Certified Semi-modular ATX Power Supply £79.98 @ Amazon UK Monitor ViewSonic XG2405 23.8" 1920x1080 144 Hz Monitor £179.99 @ Box Limited   Prices include shipping, taxes, rebates, and discounts     Total £1147.17   Generated by PCPartPicker 2020-08-27 19:59 BST+0100      

That will do.

Wait for new CPUs and GPUs, you’re friend will get a lot more value for that price then.

I'd say 3600, paired with a Strix B450-I or a B450I Gaming Plus. It'll only draw around 80W at stock at full 100% load (which won't happen in games), and can easily be undervolted further without losing much performance. The 3700X sounds like it'd be pretty overkill for what you're doing.

Unless there are HUGE performance increases (like over doubling the current performance), the 3600 will in no way bottleneck a 3000 series card.

It’s definitely worth waiting a couple months. There’s new AMD CPUs releasing in the next few months. As well as high end gpus from Radeon and Nvidia. Stock and price is pretty bad right now so that’s something which will probably get better. So you should wait but if you need a pc then this is the feedback I have to offer.
 
You can save a few bucks by going with a good air cooler like the Dark Rock Pro 4 or a NH-D15. The motherboard is more than your cpu, and it’s quite unnecessary. You can get a solid B550 or X570 motherboard for under $200. The power supply is very overpriced, stock for power supplies is bad right now so I would wait or try to look for a model with a more reasonable price. You can get a 1tb m.2 nvme ssd for that price like the Crucial P1, which is still a great ssd. 

You should wait for the new cpus and gpus, but if I aren’t then this is what I would change:
32gb ram is unecessary for gaming 3600 can run all games without struggling, so that should be fine the 2070 super performs slightly better and has raytracing, and DLSS 2.0 but you should get the rx5700xt if it’s significantly cheaper  The ROG Strix B550-f gaming is better than the MSI MPG B550 boards  
 

if you can wait, would strongly suggest to do so.

I'd look at the used market. Might be able to get a bit further that way. 

PCPartPicker Part List
CPU: AMD Ryzen 5 2600 3.4 GHz 6-Core Processor  ($139.99 @ Amazon) 
Motherboard: ASRock B450M PRO4 Micro ATX AM4 Motherboard  ($82.99 @ Newegg) 
Memory: OLOy 16 GB (2 x 8 GB) DDR4-3000 CL16 Memory  ($53.99 @ Newegg) 
Storage: Team GX1 480 GB 2.5" Solid State Drive  ($43.99 @ Newegg) 
Video Card: XFX Radeon RX 580 8 GB GTS XXX ED Video Card  ($169.99 @ Amazon) 1650S if you really can't pay the extra $11.
Case: HEC HX210 MicroATX Mini Tower Case  ($36.98 @ Newegg) 
Power Supply: Gigabyte P-B 650 W 80+ Bronze Certified ATX Power Supply  ($68.98 @ Newegg) 
Monitor: LG 22MK430H-B 21.5" 1920x1080 75 Hz Monitor  ($89.99 @ Amazon) 
Keyboard: Verbatim 99201 Wired Standard Keyboard  ($7.81 @ Amazon) 
Mouse: Redragon Centrophorus M601 Wired Optical Mouse  ($16.98 @ Amazon) 
Total: $711.69
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2020-07-16 23:35 EDT-0400

PCPartPicker Part List: https://uk.pcpartpicker.com/list/7RBpcq
CPU: AMD Ryzen 3 3100 3.6 GHz Quad-Core Processor  (£100.61 @ CCL Computers) 
Motherboard: MSI B450M MORTAR MAX Micro ATX AM4 Motherboard  (£94.98 @ Amazon UK) 
Memory: Patriot Viper Steel 16 GB (2 x 8 GB) DDR4-3600 CL17 Memory  (£73.44 @ CCL Computers) 
Video Card: Gigabyte GeForce GTX 1660 SUPER 6 GB OC Video Card  (£217.98 @ Technextday) 
Case: Phanteks Eclipse P300A Mesh ATX Mid Tower Case  (£63.31 @ Overclockers.co.uk) 
Power Supply: Corsair CX (2017) 450 W 80+ Bronze Certified ATX Power Supply  (£54.99 @ Amazon UK) 
Total: £605.31
 
I'd suggest waiting a little longer for the 3300X to be restocked, as for only ~20 quid more it's more than worth it over the 3100 imo.
 
Also, what SSD do you currently have? If it's very old and/or DRAMless and/or uses QLC flash then I'd probably also add a new SSD on the shopping list. Something like a Kingston A2000 is a really decent option for the price, coming in around the same price as SATA SSDs, despite being NVMe.

Not usually an issue. The extra power is generally only required by extreme overclockers.

That's a solid choice.
Neither. Get a 1660 Super, or a 5600XT with the 14Gbps VBIOS.
Again, neither. Get a B450-A Pro Max, B450 Gaming Plus Max, B450M Mortar Max or B450 Tomahawk Max from MSI.
CX450/550, TX550M, Pure Power Gold 400W/500W - these are all solid choices. A system with a 3600 and 5600XT (since that consumes the most power out of the 2060, 1660S or 1650S) will pull around 275W tops at full 100% load.
Ideally look for a dual-channel kit, instead of buying two separate sticks. In most cases they'll work when paired together, but it's not guaranteed, and I doubt it's much cheaper that way.
Look for some 3600MHz CL17/18 memory, or CL16 if you can fit it into your budget.
Kingston A2000 (cheapest I'd go), Silicon Power P34A80, ADATA SX8200 Pro, Sabrent Rocket, WD SN750 or Samsung 970 Evo.
Case? Phanteks P300A or P400A, Fractal Design Meshify C (though this is generally more expensive).
You should be fine with the stock cooler on the CPU and included case fans for the most part. 
Also, liquid cooling isn't the be-all and end-all of cooling, particularly if you're talking about closed-loop water coolers (AIOs).

Dont feel bad, just enjoy the board now that you have it.
 
Even its below par vrm will pose 0 issues for 2600 or 3600(x), even 3700 it will do fine, assuming youll have some airflow.
Youll have plenty of io available, whenever the need arises.
 
If you got a good deal on it (close to b450 or x470 pricing) you lost nothing since the vrm is on par with b450 boards like the tomahawk, so its not like you lose out on something (except perhaps dollars if the price wasnt right).
 
Should you have planned a ryzen 9, then yeah, it would be a bit of a bummer,  but below that, youll be okay.

Winter is the only time anyone gets static shocks here. It's probably just best to invest in a wristband.
 

Bad news is Covid has hit things kinda hard.  Everything is imported, it’s being produced, but the supply chain is overloaded and some parts are lower value while being higher shipping cost, so there are problems.  Ram and CPUs are easy to get, but PSUs and cases are in short supply.  One is heavy the other is bulky, and they’re both lower cost.  Motherboards have a different issue, they’re in flux and arranging shipping is difficult. GPUs also have a flux problem.  Nvidia is about to drop an new model, so while it hasn’t dropped yet I predict similar problems. 

Id be kinda tempted to do nothing with the thing in the very near future.  4 core still works, and gouging on parts is a bit insane for some things.  8gb memory is a bit short though. getting bigger ram sticks might actually be not the worst idea to get you to 2021 much as I hate throwing any money at all into a machine that old.  Depends on if you can get a good deal on some used ddr3.  I don’t know what ddr3 is going for atm.
 
Good news is an aftermarket cooler doesn’t do a lot of good on ryzen2.   It doesn’t overclock usefully an the stock cooler is decent.  The hard thing to get is going to be the motherboard, and possibly a PSU if it’s time for a new one.  Delaying on a gpu upgrade is the better part of valor at the moment if you’ve got anything decent already which you do.

I would go 1600af

The TDP on these chips is pretty much nonsense, if you're going to remove the turbo limit. The 9900K will pull around 160W at its stock 4.7GHz boost, and the 10700K probably around the same, or very slightly more. The 10700K will also run a good bit cooler than the 9900K.
 
As others have suggested above, I'd wait for Zen 3 to come out and make a decision then.

ignore these tdp numbers, some of these chips will use double the tdp in normal usage
 
Can you get a 9900k cheap? If so go for it, else, Id probalby wait a bit.

1. NVidia's next gen graphics card are due the end of this year (maybe AMD since consoles have their new architecture), if your current system can still hold up, dont upgrade yet. Also AMD's next gen CPUs are due around that time frame.
 
2. Unnecessarily overkill PSU
 
3. 2x16GB is better for overclocking, though I get that 4 sticks look better.

PCPartPicker Part List Type Item Price Memory G.Skill Ripjaws V 16 GB (2 x 8 GB) DDR4-3600 CL16 Memory $99.99 @ Newegg Canada Storage Team GX2 512 GB 2.5" Solid State Drive $69.99 @ Newegg Canada Storage Seagate Barracuda Compute 2 TB 3.5" 7200RPM Internal Hard Drive $74.75 @ Vuugo Video Card ASRock Radeon RX 5700 XT 8 GB CHALLENGER D OC Video Card $528.50 @ Vuugo Case Phanteks Eclipse P300A Mesh ATX Mid Tower Case $99.99 @ Newegg Canada Power Supply Corsair TXM Gold 750 W 80+ Gold Certified Semi-modular ATX Power Supply $154.99 @ Canada Computers Monitor Acer VG240Y Pbiip 23.8" 1920x1080 144 Hz Monitor $255.99 @ Canada Computers   Prices include shipping, taxes, rebates, and discounts     Total (before mail-in rebates) $1304.20   Mail-in rebates -$20.00   Total $1284.20   Generated by PCPartPicker 2020-06-16 21:25 EDT-0400   Wait until July 7th, when new AMD CPUs and B550 releases.