First off, wait until DX10 cards come on the market. Second, see how much power your parts will need and add 100-200 watts and add 10-15 amps on the +12 volt rails. Lastly, get a full size ATX or BTX case, they stay cooler and are much easier to install things into.
And try to make sure that each stick of RAM is the same type/speed/latency.
"No, Mama. You can bet your sweet ass and half a titty whoever put that hit on you already got the cops in their back pocket." ~Black Dynamite