You should get decent framerates in 720p for at least 4-5 years, it's a lot less demanding than 1080.
You'll probably get 60-100 fps depending on the game if you disable Vsync. That doesn't mean you can see them - a 60Hz monitor will only display up to 60fps.
yes it is 60hz.... --- Post updated --- Should I get this instead of the 970 ? http://pcpartpicker.com/part/asus-video-card-strixgtx960dc2oc4gd5
VRAM != performance. The GTX 960 is a much worse card than the 970. Price/performance is only slightly better and the 970 will run mostly anything maxed out @1080p60 while the 960 won't. That said, you really should go with AMD instead. If your budget is ~$200, get an R9 380, it's better than the 960 in every way. If it's $300-350, go for an R9 390. Higher TDP than the 970 and slightly worse in DX11 but much better DX12 performance. Or wait for Polaris/Pascal.
The new AMDs will come beforehand and will most likely be a lot better performance wise than the Nvidias. Seriously, does that case have such a bad airflow?
I wouldn't bet on it. Both are looking to be fiercely competitive. I'd wait until both come out before deciding a winner.
Here's a part list: 1934CAD http://ca.pcpartpicker.com/list/F2mvjc i5 6600k, 16GB of DDR4, EVGA 1080SC. Will run Beam at high settings @60FPS+
