Which would be fastest for gaming? The AMD option seems best but its a bit more expensive; would there be a noticeable difference in performance between the setups? Or would they perform about the same, making it a waste of money to spend more on the AMD option?
I would go for 4670K with a 7970 if I were you. It's the best option there for bang for buck. On the other hand, you can go for 8350 with 7970 and still have great performance on either front. So either choice is good.
So the AMD option 659-679 dollars. Intel option 650+ dollars. So you will get a faster single threaded quad core and a slower GPU with the intel option. AMD option you will get 8 cores( Each core isnt as fast as intel but you get 8) and the 7970 is faster than the 760 which is better for gaming.
Also what games are you playing? What Resolution? is it 60hz or 120hz?