EDIT: Most of the stuff seems a bit overpriced to me, I think I can build a better rig for $2000. And assuming it's a for a monitor resolution of 1080p, there's no need to spend more than $1500 or so to get great performance and quality. If it's for a lower resolution, the remaining $500 should be spent on a good 1080p+ monitor. The list already contained an SSD.
Its all about balance. choosing a GTX680 and then going for a 650W PS doesn't cut it. Been a long time since i put up a rig together, but this is what i would go for. There is still room left for a GTX680 should you choose to go for it. Cheers.
This rig would perform the same for over $300 less. Add another 7950 3GB if the resolution is >1080p. Add a 1080p monitor if the resolution is <1080p.
Future proofing. why cut it so tight. what if the user decides to go for CF/SLI in the future ? It would. You went for 8GB. and Air. a WD green ?? Common. They are s l o w (not to mention mine died after a year). Corsair TX series is known for its reliability, again, personal experience.
8GB is enough for gaming. Air cooling is much better price/performance than contained water cooling, and 212 EVO cooler is quieter than a Hydro. Even if Hydro will cool better, it'll still be crippled by Ivy Bridge's heat output, while 212 EVO will achieve 4.5Ghz on a Sandy. 5400RPM drives are fine when you have an SSD as a system drive. That's my experience, at least. Not only is it fast enough, but my 5400RPM Caviar Green has had zero issues in the 3 years I've had it. Antec Earthwatts is also known to be reliable, but personal experience has no say in that matter. People have 'reliable experiences' with crappy PSUs.
But 2500K+670 would be nearly as fast as 3570K+680 and much better bang for buck. 7870 CF is overkill for 1080p