Of course, I'm using a good PSU, rather than a shit one. yay Earthwatts.
Anyway...
650 is more than enough, and the PSU is higher quality than whatever you had. Corsairs are fucking wonderful PSUs.

HDs... Replace the Baracudas. Seriously. Get some form of WD or Hitachi. baracudas have been having reliability problems for about two lines now, and don't seem to be letting up. =\