Olagine

I ended up going with this case.
https://www.amazon.com/CORSAIR-CARBIDE-SPEC-OMEGA-Mid-Tower-Tempered/dp/B077GCKBV3/ref=sr_1_1?ie=UTF8&qid=1529605630&sr=8-1&keywords=Carbide+Series®+SPEC-OMEGA+Tempered+Glass+Mid-Tower+ATX+Gaming+Case&dpID=41XHNGy8YvL&preST=_SY300_QL70_&dpSrc=srch
 
It probably doesn't have the world's best airflow, but it looks pretty cool. I actually ended up buying all the parts i needed yesterday; thanks for the recommendation though!

I wouldn't go with that one - read that it's an absolute sucker for airflow (I mean the front isn't great, just look at it.)

Speaking of suckers, I'm a sucker of Phanteks and Fractal Design, so you could check them out (the Phanteks P400/P350x depending on your budget or IMO the Meshify C (much better airflow) from Fractal). You could look for alternate cases from reviewers like Hardware Canucks or Gamers Nexus or pretty much any forum. People also recommend the Enthoo Pro Midi M, although it's a bit more expensive than the other ones.

Corsair hasn't made any good budget cases lately, but you could look into the Corsair 275R (although from my perspective it doesn't have great airflow either, you'd have to read about it).

He can always get a secondary display down the line. 21:9 1440p perhaps?

It's okay, but you might want to move up a tier or two in the PSU tier rankings.
 
 
Other thing: why the 8600k? Generally either the 8400 or the 8700(k) are the suggested options in the 8th Gen.

Mushkin NVMe are far cheaper for only a slight reduction in perfromance...
 
Sorry on mobile... Having trouble with controls

I don't think I will need an M.2 because from what i've seen people say the boot speeds for windows is pretty negligible and that's basically what I want my SSD for aside from a few games that would benefit from a faster load speed. NZXT is a bit more expensive even though they're more sexy so I have to take no on that one. I don't need more than 1tb of HDD as my current computer has 1tb of storage and only recently have I used a lot downloading games. I currently have about 144GB left of storage and that is with a shit ton of stuff I probably don't need. As for the fans I plan to get however much HD140's for the case and HD120's for the AIO.

It's a decent unit. Replace it when it starts to show issues. It should last quite some time.

I struggled with that no reviewer seems to have done a test, I went with the drp3 because it was 40usd, but if they are the same price just go for the drp4, you will get better support from be quiet, and better re-sale value in case you want some flashier in 3 years. I doubt temps will be much different anyways. 

Difference in degrees can't be directly compared between different reviews. 40c vs. 42c  represents a bigger difference in cooling than 60c vs 62c. As more heat is used and the closer the heat reaches a cooler's maximum cooling capacity, the larger the separation in degrees is shown between coolers. 
 
You mentioned 10c which is probably from a Tom's Hardware review. https://www.tomshardware.co.uk/be-quiet-dark-rock-pro-4-cpu-cooler,review-34292-2.html
If you look at the difference in temps shown, the gaps are larger compared to other reviews of the same coolers. This is because they're pushing near the limit of the coolers' capacities as shown by the MA610P just being able to keep temps at 74.5c despite 100% rpm. At more reasonable loads, the differences minimize towards the 1-3c that you see from other reviews. 
 
The DRP4 is quieter but seems to perform a bit worse due to lower rpm fans. It's a small difference in most cases. 
For the same price, I'd suggest going for the DRP4. It's an overall better cooler. If you want more performance, there are probably better alternatives available. The strength of the DRP coolers lies in quiet operation while not being far off of the other dual tower kings.

Yup. Defo the 8400. Others say get an older i7 - you can, but I don't recommend it , unless it's a really killer deal. The i5 is with 6 cores and 6 threads will set you good for a long life, and it'll have warranty and it's generally safer to buy than used.

his is overclocked by like 1.2 ghz i believe
two cores WILL hold you back but that is a pretty nice overclock 

yah thats good, just scrap the AIO and stick with your current cooler because thats a locked CPU so there is no reason for the AIO IMO

Thanks Already found a video of how to disassemble it, but tbh I didn't know that iFixit sells replacement parts ;p
 

It depends, if you are confident you can fix it go for it