A Seasonic 380 or Corsair CX 400 or especially the Corsair VX 450 should be enough for your system with a 9600GT.
Frankly I would recommend a Glacial Power 650 as your best bet. It costs around 4.5k but would be good enough for an oced i7/C2Q + 5850/5870 + with room for other goodies though that would make it perform at its peak.
Frankly I would recommend a Glacial Power 650 as your best bet. It costs around 4.5k but would be good enough for an oced i7/C2Q + 5850/5870 + with room for other goodies though that would make it perform at its peak.