Suggestions for my rig?

I would switch that OCZ Agility 3 with a Crucial M4. <-Crucial M4 more reliable than Agility.

Drop the 7970 and go for a GTX 670. <--- save 60 bucks for near similar performance.

With the money you save from getting the GTX 670 instead of the 7970 - you could get yourself a 256GB SSD.

Other than that...looks good.

Edited.
 
1: do you really need 16gb of ram? 8gb is usually more than enough to handle most tasks
2: get ivy bridge. they are faster than sandy bridge clock for clock
3: seagate barracuda 1tb with 64mb of cache is faster than the black drive and chepaer
4: a gigabyte z77x-ud5 is about the same as the sabertooth but 50 bucks cheaper
5: get a asus directcu2 670 or a gigabyte windforce 670. they perform close to a 680 but for 100 bucks cheaper
6: a case like the antec 302 or p280 is much cheaper and have the same build quality. the non-silent version of the p280 is the 1100
7: why do you need 1000w? go with a 650-750w psu. it wil be more than enough to power your cpu and 2 670 or 680s. a good one is the ocz zt750w. its a 80+ bronze version of the zx series
8 a cooler such as the hyper 212 is about as good as the one that you included. i just recommend getting some more silent fans and doing push pull on the heatsink.
9: get a mushkin chronos deluxe 240. not only is it faster than a crucial drive, but its also under 1$/gb. i have one and it just super fast. the eqivalent drives to the chronos deluxe is a vertex 3 max iops or patriot wildfire

hope you follow my suggestions