Well it depends on what you'll be playing. If you'll be playing games like Battlefield 3, Battlefield 4, GTA V (if it ever comes out on PC), and some other games like that. 2 770s is safer to go with, as they're more powerful and with a nice OC do take the lead over many other cards in the market. As I said, SLI 770s will get you around 110 fps in BF3 stock speeds, then with a decent OC, you'll get some 10 or so extra frames. In a very graphically demanding game like Metro: Last Light, you'll get around 60 fps, then again, your overclock will give you a little boost. Your monitor will only display 60fps if it's 60hz. So anything around 70 FPS is safe and more than playable. And as I said, you can just go for 2 way SLI 770s, max out every game you play, and then maybe in 2 years you add a third one. 3 760s will perform similarly to 2 GTX 770 Lightning cards basically. Not a huge difference.