That's a very good power supply. If you don't have to have a modular, the OCZ StealthXStream OCZ600SXS 600W will supply more amps at the same power rating. It's very reliable, efficient, and it's cheaper at $79.95 ($64.95 after $15.00 Mail-In Rebate).
The Zalman version of the XFX 8800GT Alpha Dog is another good choice. It offers better cooling than the standard coolers available on them.
Everything else looks great. Should be a great performer.
Yeah I'm pretty excited. This'll be my first build. Because this is a computer for my entire family and my mom's paying, we might get 4GB of RAM now and add more later, but I guess that's not a huge problem. We'll see.
Yes! I used to have a reference XFX 8800GT, but the cooler was useless, 90c at load and quite noisy too. I was just going to replace it, but then I found out about the card in my sig. It has a sweet spiral cooler and a voltage jumper. I wrote a review here: http://www.computerforums.org/showthread.php?t=70301
My first attempts at overclocking the card weren't very succesful, but the voltage jumper fixed that (read on after the conclusion).
Don't get a reference design whatever you do.
I don't really think you need 8GB of RAM though, but make sure you get a kit with CAS 4 timings.