I definitely choose a quality (not stock) PSU, Antec, FSP Group, OCZ, PC power and cooling, were some of the better brands I've heard of. Never skimp on the PSU, if your PSU fails it can take all your hardware with it. here's a wattage calculator: eXtreme Power Supply Calculator Lite v2.5
A personally would go with an ASUS, I have an MSI board and I don't like it, but mines a budget board. It got good reviews and if you like MSI go for it.
are you going to OC any? if so go for some higher quality DDR2 800 ram. if not, DDR2 800 is still very close in price to 667 so it could be a little performance boost.
Nice, have fun.