Don't listen to the people that bash the lesser known PSUs and demand you get a high-priced name brand.

Important things with the PSU is the amps on the 12v rail and the amount of variance. You don't want one with low 12v amps or one that can't keep a steady flow.

Rosewill is a find brand. I use it personally (a 550w) and I know alot of other people that use them too. Unless your running a huge amount of components in your case (which you arent), or have a pool full of cash you swim in every morning, keep the Rosewill and same some green.

As for the ram, are your really sure you need 4gbs? Id do some more research and see exactly how Vista acts under 2gigs and 4gigs. 2gigs will run you ~$100.

The rest of your stuff looks fine. Good luck with the build.