well some of us just built a cheap 939 systemI would have a hard time recommending that you put any more money into a Socket 939 system.
I just built this system less than a year ago.. but it was before the AM2 socket came out, I already had $$$ ram.. so I am not going to blow a ton of money for a new mobo and ddr2 ram... I would rather toss the best chip i can get for the board on it and sport that. Im pretty sure that a nice x2 chip, my 10,000rpm rapter and the 512 meg video card should leave me in good shape for another year...
Best you can get for 939 is X2. The FX isnt worth the money, its just an X2 with a fancy name. If you dont wanna OC, you can get the X2 5000+ i think it is, the top end X2 and it will be cheaper then the FX-62 but its the same thing. If you can OC, you can get the X2 4000+ and OC it to perform the same as the FX-62.