Buy a "PC Power & Cooling" PSU - it's worth the money. I've given up on all the others, but I have an old one which has lasted over 10 yrs. I just bought a Silencer 470 ATX ($99) for another PC. I've had bad luck with other brands. Buy online at "http://www.pcpowercooling.com/home/". No, I don't work for them or know anyone there.
When talking PSUs you need to be as specific as possible. Almost all PSU mfrs have multiple lines of PSUs of varying qualities. What's your budget for the PSU? Do you have a link to your supplier? How opposed ar eyou to going with a different vendor and where are you located?
I have taken a bit of a shine to the Antect Neo HE 550W which is about $180AUD.
After that I thought a true power2 seems to get a lot of good press, and from there I thought the Neo HE sounded even better.
What kind of motherboard you using? I have been in market for awhile now for a power supply myself. I also looked at the Antec HE 550w, but if your using an ASUS A832N-SLI or A8N-SLI/Deluxe/Premium board, the Antec HE Series doesn't work with them. They randomly reboot those kind of boards.
I can't remember where I read that, or I would have posted a link.
I just bought an OCZ Powerstream 520w for $134.99, everyone pointed me in that direction, and I plan to use the same vga your going to use (7900GTX, BFG flavor)