Fry's has the Antec Neo 480 for $49 AR until Tuesday. This is a smokin hot deal and would fit your build nicely.
The OCZ Modstream 450 is $89 shipped from Monarchcomputers. I have been looking the last few days for a Fortron 500 Bluestorm, but can't find one in stock anywhere.
Any of the 3 mentioned would work well (24 pin, PCI-e, good rails)
m 🙂