Unless you've got some odd stuff you ain't mentioned, (didn't see what kinda burner or DVD gear you've got).  I don't see why a 400w couldn't push that just fine.  Don't get me wrong bigger is better but who can allways go way out.  a 1000w would be real sweet but who can go for that (within reason).  Here's a helpful link from AMD take a gander http://www.amd.com/us-en/assets/cont...docs/26003.pdf   Hit it about page 11 to 15.  There is some cool stuff to read and help you spec this out.  Actually anyone building a new rig should at least take a look.  It's some good sh!t I think Sounds like a real sweet rig.  Don't have to much fun with it.