Also, do you plan to overclock the cpu? (the liquid cooling kit would suggest that you do, yet a non-K cpu has very limited overclocking potential). Also, what OS are you planning to install, and how? I notice you didn't include an optical drive.
The i7 is only useful when you need the extra threads, which in gaming you don't.
If you want to stick with Nvidia, get a 670. Its 95% the performance of a 680 for $100 less, can even overclock it past 680 performance. Though yes, the 7970 will outperform the 680.