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.
![Very Happy :D](./images/smilies/icon_biggrin.gif)
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. =\