Here's a suggestion for PSU:
NCIX.com - Buy Antec High Current Gamer 750W 24PIN ATX12V V2.3 Active PFC 80 Plus Bronze SLI Power Supply 135mm Fan - Antec - HCG-750 - in Canada
I haven't gotten around to buying an Antec HCG but it has surprising efficiency for a 80+ "bronze" and pretty good arrangement of its rails:
Antec High Current Gamer HCG-750 Power Supply - Cabling Arrangement & A Look Inside :: TweakTown USA Edition
That should handle dual GTX 460 with some room to spare (e.g. don't upgrade to dual of the highest end GPUs).
I have no issues with the rest of the build. If you don't horde videos and only keep the games that you play installed, then a single 120GB SSD may be fine. I'd advise however to get a 7200RPM hard drive to store games, because I'd just barely overflow my SSD if I put my games and data on it.