I'm running msi gtx 970's in sli with a 750 watt psu. Also core i7 4790k oc to 4.6 ghz,6 case fans, corsair h105i watercooling, 256gb ssd + 1tb wd hd and red led strip.
My screen refresh rate is 60hz so All my games are limited to 60fps, but i'm very happy! All my games run smoothly at 60fps including assassin's creed unity, the crew, evil within etc... all at ultra everything.
Wolfenstein does ignore my second card but on everything maxed out ,even shadow quality, it still runs at 60fps smoothly, looks very beautiful I might add.
It's overkill at the moment but definitely future proofs your pc for a good price.