GoldenLeaf

If anyone is interested in what I eventually went for this is it:
 
PCPartPicker part list: https://uk.pcpartpicker.com/list/Q2FLKB
Price breakdown by merchant: https://uk.pcpartpicker.com/list/Q2FLKB/by_merchant/
CPU: Intel - Core i5-8600K 3.6 GHz 6-Core Processor  (£235.20 @ Aria PC)
CPU Cooler: be quiet! - Dark Rock Pro 4 50.5 CFM CPU Cooler  (£67.07 @ CCL Computers)
Motherboard: Asus - ROG STRIX Z390-E GAMING ATX LGA1151 Motherboard  (£223.65 @ Amazon UK)
Memory: Corsair - Vengeance LPX 16 GB (2 x 8 GB) DDR4-3000 Memory  (£126.95 @ More Computers)
Case: be quiet! - Dark Base 700 ATX Mid Tower Case  (£152.49 @ CCL Computers)
Total: £805.36
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2018-11-29 19:45 GMT+0000
 
I went slightly over budget (by over £200 haha) but hey it should last me a while again.
 
Thanks to both of you @brob and @Zando Bob. It had been a while since I had built a new PC and you really pointed me in the right direction.
 
New parts will all be arriving tomorrow for me to build this weekend. Wish me luck!

If anyone is interested in what I eventually went for this is it:
 
PCPartPicker part list: https://uk.pcpartpicker.com/list/Q2FLKB
Price breakdown by merchant: https://uk.pcpartpicker.com/list/Q2FLKB/by_merchant/
CPU: Intel - Core i5-8600K 3.6 GHz 6-Core Processor  (£235.20 @ Aria PC)
CPU Cooler: be quiet! - Dark Rock Pro 4 50.5 CFM CPU Cooler  (£67.07 @ CCL Computers)
Motherboard: Asus - ROG STRIX Z390-E GAMING ATX LGA1151 Motherboard  (£223.65 @ Amazon UK)
Memory: Corsair - Vengeance LPX 16 GB (2 x 8 GB) DDR4-3000 Memory  (£126.95 @ More Computers)
Case: be quiet! - Dark Base 700 ATX Mid Tower Case  (£152.49 @ CCL Computers)
Total: £805.36
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2018-11-29 19:45 GMT+0000
 
I went slightly over budget (by over £200 haha) but hey it should last me a while again.
 
Thanks to both of you @brob and @Zando Bob. It had been a while since I had built a new PC and you really pointed me in the right direction.
 
New parts will all be arriving tomorrow for me to build this weekend. Wish me luck!

Gigabyte B450 AORUS PRO WIFI (rev. 1.0) and MSI B450 GAMING PRO CARBON AC have Bluetooth and WiFi. They are under £150.
 
This is very broad and a bit generalized. Modern cpu consist of a number of "cores". These are the primary execution units. Leaving out simultaneous multithreading/hyperthreading for the moment, if a cpu has two cores it can execute two threads (series of program steps) at the same time. Multithreading/hyperthreading allows a core to execute a second thread concurrently, but the result is not twice the performance.
 
The most recent data I have seen suggests that Intel Coffee Lake cores can process roughly 5% more instructions per cycle (IPC) than AMD Ryzen 2xxx cores. As a result at the same clock speed an Intel core slightly outperforms its AMD counterpart. Given cpu with roughly the same clocking profile, this difference is not really noticeable in most general applications, games, etc. But it is real and can make a difference in some situations.
 
Very roughly, in gaming a 2600X is equivalent to an i5-8400. Since the 2600X has multithreaded cores it will offer slightly better performance when doing things like opening twenty Chrome tabs.

On the Z370-A, it's easy as pie. I just activate the XMP profile for the RAM, change the CPU ratio to 50, then up the voltage a bit, around 1.32 should be fine for 5Ghz, I don't think I did anything else. Did mess with other settings and stuff to get to 5.1, but for a basic overclock it was incredibly easy. 

8700K, Dark rock pro 4 and Corsair 16GB DDR4 is about £550on part picker and would still need a case (was thinking a be quite one) and mobo. Mobos look more expensive than they used to be. There are so many to choose from and all look very similar, especially the Asus ones. tbh I have never OCd myself before. I had my current PC from a builder site that OCd my current 4770k to 4.3Ghz and I realised after a while that it wasn't stable and re-set it. That's my only concern, having instability issues. Yeah I want to go aircooled now as I am fed up of the whine I get from this H60 cooler I have.