I am using DDR2 533 on my Athon x2 64 3800+, soim sure you cna use something lower in just DDR (dont take my word on that though). I think you should go up to a 400W true output PSU at least, just as that will be sure to cover anything + fans.
What are you gonna use the pc for? Are you sure you dont wanna get a x2 3800 for a bit more money? It would probably make your computing experience much more enjoyable. Unless you just run office apps on it
Well, this is really for a family member, whom will probably be surfing the internet and maybe using a few office applications. His current rig predates the pentium 3 I believe. He wants something affordable, and I want to give him something that will do what he needs and be upgradeable if he decides to do more with the PC.