amd build vs nvidia build

Nvidia 770 and AMD 280x get about the same performance overall, although I am partial to NVIDIA because my 760 HAWK from MSI hits 1300 overclock lol I would say you're good either way. If you want an opinion, mine would be with the 280x though, as it has 3gb of VRAM, and will be more future proof.
 
Go witht he Nvidia build because yes the R9 280x has 1gb more VRAM then a reference 770, yours has 4gb so it will be more future proof. It also helps that it is a slightly cheaper build.

On a side note why a sorta custom loop? Something like an H100i would work or I would recommend something along the lines of Kraken X60 or Swiftech H220 if you can find one. An H100i or H110 would be plenty for the setup. I understand that you might want to later add on other water blocks but if you are not going fully custom and everything water cooled now, then it won't be worth it a year down the line. Just a thought.
 
Depending on your resolution, the 4GB GTX 770 is probably a waste of money. The 2GB GTX 770 gives the same FPS, and it costs 70$ less. Future proof is speculation, in reality putting "future proof" and "graphics card" in the same sentence is kinda silly.

Truth is with modern games - from 2gb to 4gb you won't notice any difference.

The 280X is still pretty high above MSRP. If you want to sli/crossfire as a possibility go with the Nvidia hands down.

I would also go with the Gigabyte motherboard - but thats just me.
 


I realize future proofing is impossible but the 4gb gives flexibility if he ever wants to upgrade monitors to possibly 2560 x 1600 and it will benefit in multi monitor setups. If sticking at 1080p then 2gb is fine, but if 4gb is in the budget then it is an option if the op ever wants increase the resolution.
 
The 4gb 770 is great but it will only be able to access about the same amount of ram as the 280x due to its memory bus.

In the end, both are great and you won't go wrong either way. Like I said, I prefer the 770 because of my history, but don't choose it because it has more memory, it effectively doesn't.
 


More speculation. So it might give more fps on a 3 monitor setup but the frame rate is still unplayable.

Please show some statistics or articles that prove your point here - I would like to see them.