Eh you'd probably be just fine with a 375W PS...mines only 400W and im using 2 CDROM drives, 2 hard drives, a 9800GT, athlon x2 4400+, etc...

Honestly the power supply rating requirements these days are f'ing retarded. Most people think you have to have a huge powersupply to do anything...back in the day I used to run 2 HDs 2CDROM drives from a 230W and people still claimed it wasn't possible without a 300W...