I'd not recomend a 512mb 6800U, for reasons stated in your other post. Also, what 2gb of ram? I'd suggest not getting something too expensive, but make sure you have 2x 1gb chips and not 4x 512mb. Also also, that is one VERY expensive power supply. I don't think you need quad 12v rails, unless you are running something like 2 7800GTX's or 2 6800U's in SLI, and have a ton of drives.
I have this power supply, and it is more than enough for my needs:
http://www.newegg.com/Product/Product.asp?Item=N82E16817104934
Or, you could go with this one:
http://www.newegg.com/Product/Product.asp?Item=N82E16817104152
As far as motherboards, I would suggest one of these 3:
http://www.newegg.com/Product/Product.asp?Item=N82E16813136152 - Excelent overclocker, good price.
http://www.newegg.com/Product/Product.asp?Item=N82E16813136157 - Same as above but with more Sata ports and supports SLI. I wouldn't recomend SLI, but many people go for the SLI board simply to spend more money.
http://www.newegg.com/Product/Product.asp?Item=N82E16813131540 - Supposedly a more than decent overclocker, but the main reason I'd get this one is if you want a very quiet pc. Replacing the stupid northbridge heatsink on the DFI is hard, because its right under the video card.
EDIT: I just noriced the (sli) in parenthesis after the 6800u. Does that mean you are getting 2x512mb cards, or 2x256mb cards? Or are you just getting a single 6800u? Either way, I'd recomend a 7800GTX over a 6800 ANY day, and you can still add another for SLI if you want, but I think its rediculous since it can already run Doom3 maxed out at 1600x1200, 4x AA and 16x AF.
http://www.newegg.com/Product/Product.asp?Item=N82E16814127187