From your other thread - going from a C2D E6600 and 8600GTS to a C 2 Quad and HD 4850.
Going from a 2.4Ghz C2D E6600 to 2.66Ghz C2Q Q6700 is really not worth spending even $76 for a used CPU. A better option, IMO, is to overclock that E6600 to something like 3Ghz and get that HD 4850 upgrade.
For a new PSU a couple good choices that will get the job done nicely. Corsair 400CX / Corsair 450VX / OCZ Fatal1ty OCZ550FTY 550W / OCZ ModXStream Pro 500