Trying to decide on a video card

Solution
a gtx 1070 would do a fine job.
looking at your build, I'd scrap the 850W PSU for a 550W unit of better quality like the EVGA G2 or Corsair RMx/RMi
I agree with Isokolon that the 1070 would be a great option for GPU as it should handle most all games for 2 or 3 yrs. at a minimum. EVGA are a good PSU again he's correct the G2 or P2 in the EVGA line are a better choice but stick with a 600 or 650w incase you need to add something in the future. The thing I noticed is that you're paying almost $100.00 for your OS when you could get the OEM version of Windows 10 Pro for about half of that. I got mine from Amazon seller Smart Digital Inc. for 54 bucks it came with a genuine Microsoft sticker with new activation code. The biggest thing to do when purchasing a less expensive OS is to read the seller review page and stick with a seller that gets good reviews. 40 bucks is 40 bucks after all.