Nice build. The only thing that I would suggest is going for the 670 rather than the 680. Their specs are so close, you can OC the 670 and be neck and neck with the 680 and the 670 is over $100 cheaper.
You really could scratch the black edition WD HDD and just get a Seagate Barracuda. No difference in performance only a name. PSU will be fine only if you plan not to SLI later on, then up that to a 750W.
I have that exact model of the Barracuda and have had it for over 3 years. Haven't had a bit of problems. Its really just a luck of the draw deal as it goes with all pc components. You win most of the time and you lose a few times.