The only problem I see is that you are using a green drive as your primary storage. You'll be disappointed in the performance of that drive, and you'll also be waiting all the time for the drive to spin up because it sleeps so aggressively. Get yourself a black drive - it's worth the extra money.
A pair of GTX 580s will pull about 450W max while gaming, but can pull up to 625W under full load, and that's just the two cards. So I usually recommend an 850W PSU if you are really planning to SLI.
On the other hand, if you are not planning to SLI a good 650W would do fine. The TX750 V2 is an excellent PSU, but it's more suited for GTX 570 SLI or GTX 560ti SLI.
Or 6970 crossfire.
And you will want a cooler for overclocking. CM Hyper 212+ would be one.