1 GTX 970 will be better then the 2 760s
Paying the premium for an LGA-2011 and DDR4 ram gives you nothing in gaming/FPS.
Using wifi in generall is going to drop your gaming ability down, using a $5 usb wifi adapter on a $1800 computer should be considered a criminal offense.
In all seriousness though, if you just cant do etherent, then get a 500-600mbps powerline adapter. They run $40-60 and will provide you with much better latency/ping times vs wifi (latency is far more important then mbps in gaming). I know the mbps is the speed but you should look at mbps as the amount it can carry in one trip and latency is the speed. In gameplay you dont need to send massive amounts of data, you just need it instantly