That PSU isn't really overkill, its overpriced and unfortunately suffers from ripple under 400+W load(which for a unit rated @ 700W is quite bad, especially since I owned one ><).
You can't go wrong with corsair... ZZF has several models priced better than the other etailers; HX620 for $124.99
(after $20MIR), the HX520 can be had for $98.90
(after $10MIR), and the VX550 for $78.90
(after $15MIR) and they all ship free
Here some Jonnyguru reviews
for the various corsair models, HX series = modular; VX non-modular cabling. IMHO corsair(aka seasonic) makes some of the best PSUs on the market.
The only other item on your list I take issue with is the GFX card... You can pick up better performing, cooler running and cheaper card(s).
XFX PVT88GYDF4 GeForce 8800GTS (G92) for $299.99 after $20MIR + free shipping
Linskingdom has a great 8800gt(G92) info thread
, to help you out... Long story short, that XFX 8800gts is only ~$20-$30 more expensive than any current 8800gt. So I would probably buy it over an 8800gt, since you get 128SP(stream processors) 16 more than the 8800gt and a dual slot cooler which is far more effective and quieter to boot.
Finally, I would buy an e6750 over an e6600. First the e6750s are guaranteed G0(G0=stepping; which means they have a higher thermal spec @ 72Â°C and generally OC better). Also, they are somewhat cheaper ($189.99
) and if you don't plan on OCn immediately they have a higher stock clock speed(2.66ghz).
Everything else looks good