Thats a pretty powerful system, but I do have a couple thoughts.
For gaming, there is absolutely no advantage of an i7 over an i5. The difference of the i7 is that it uses something called "HyperThreading", what this basically is, the CPU "pretends" to have more cores than it actually does, to split up some of the workload. Now both the i5 and i7 are quad cores but the i7 can "pretend" to have 4 more.
The thing with games is, no game on the market is capable of using this HyperThreading technology. In fact there are only a couple games on the market that use all 4 of the real cores on a CPU yet. Which means, if you wanted to save a little bit of money you could use an i5-3570K Ivy Bridge and get results just as good when playing games.
The 7970 is a very powerful video card. However, perhaps with the money you save by going with an i5 you could afford the new GTX 680?
Other than that, your system looks like it will be pretty awesome. 16GB is probably more than you need, 8 is plenty, but then again I'm not one to talk as you can see in my signature I have 16 too.