Hi, lol, I have been posting on here alot recently because I am throwing alot of money into a gaming pc and want to know if what I am getting is going to be as beastly as I think.
I have a 1080p 144hz benq monitor but am looking to buy a 4k monitor in the next year or so.
If I were you, I would wait until the next release of cards from Nvidia and AMD. Also, I would avoid SLI/CF for the time being. The profiles are finicky, and in some games it's not even an available option until a profile is released.
If you can't wait, a 980ti if you prefer Nvidia is a solid card. If you're open to AMD, a Fury X or regular Fury OC'd is also a solid choice.
Edit: As for the PSU, if you insist on running a 2 card setup, I think an 850 will be fine, but I myself would probably up it to 1000w to keep some head room. But that's me.
Do not do SLI, I will never do that shit again, issues range from not supported in games, poor support in games, must be in surround when doing multi monitors or else you don't get sli.
In 4K with the newest drivers, FuryX slightly outperforms 980Ti. On 1080p the other way around... If you are to SLI, I'll advise you to Crossfire, since A) the scaling is better than SLI and B) in DX12 you can use 2 GPUs natively, and then amd outperforms Nvidia. So I would go amd on this one...