Dual GTX 970 ftw or Single GTX 980 SC

Solution
For your build I would get at least a 250GB SSD (like a samsung 850 evo) because all the AAA titles are like 50-60gb now.

Instead of the wifi adapter (which might be a pain cuz of drivers) I would get a mobo with built in wifi.

Lastly I just don't think it makes sense going balls to the wall with 1080p rig when it's decidedly last gen at this point. You are spending 1k on a 1080p SLI rig. If you wait till next year you'll be able to get a next gen titan and a 4k ips monitor for 1500.

IMO 120hz/144hz is a stop-gap. It's basically the industry's way of saying that we don't have the power for 4k but we have way more power than necessary for 1080p 60fps.

To recap issues with 970 SLI is they have the brute force for 4k but the 3.5/4gb...
For your build I would get at least a 250GB SSD (like a samsung 850 evo) because all the AAA titles are like 50-60gb now.

Instead of the wifi adapter (which might be a pain cuz of drivers) I would get a mobo with built in wifi.

Lastly I just don't think it makes sense going balls to the wall with 1080p rig when it's decidedly last gen at this point. You are spending 1k on a 1080p SLI rig. If you wait till next year you'll be able to get a next gen titan and a 4k ips monitor for 1500.

IMO 120hz/144hz is a stop-gap. It's basically the industry's way of saying that we don't have the power for 4k but we have way more power than necessary for 1080p 60fps.

To recap issues with 970 SLI is they have the brute force for 4k but the 3.5/4gb ram is a limitation and SLI means you need games that are really optimized for it to get all your moneys worth.

I would get a single gtx 980 (and overclock it) with a 1440p monitor (like a qnix qx2710 dvi-only). The qnix overclocks to 96hz so when you got the extra fps, you can increase the refresh rate. Most importantly 1440p has 50% more pixels than 1080p so the image is a lot sharper. it's a good hold-over till 4k becomes more mainstream next year.

 
Solution
My single 980 OC'd in BF4 gets 90 FPS on 1080p and 60 FPS on 1440p. From what I hear with the witcher 3 you will get at least 60 FPS on Ultra if you just disable hairworks. On the flip-side, the Witcher 1 is so old (and thus poorly coded) that with mods I only average 96 FPS (70 low, 125 high) on 1440p.