I use 6400 3.2GHz X2 in all my systems.

Gygibyte is quality company. I use MB's with heat pipes though.

Ya I dont think you lose much going from 4 cores to 3 as long as the clock speed is the same, some will have different opinion.

I dont have Win7 but most say its great. You can still get the beta from what I understand.

Few are familar with Pheons nowdays. Everyone is going Intel I7 / 920 / X58. Thats why few answer.