Rosewill is crap. Get rid of that PSU. Instead- Corsair 550VX or PC Power and Cooling 610W.
Get rid of that motherboard. nVidia's Intel chipsets are crappy, and you don't need SLI anyway unless you are gaming on a monitor of at least 24". Instead look at this board:http://www.newegg.com/Product/Product.aspx?Item=N82E16813131299
One 8800GT now, stepup to a 2xx series card using eVGA's program in 90 days.
4GB of RAM DDR2 800 4-4-4-12. 2GB is fine, 4GB is better as cheap as RAM is.
Make sure its HomePrem for Vista. Home Basic is terrible.