hello i have a AsRock 785gxh/128 Athlon II X2 260 3.2GHz CPU, 4gigs of ram and a gt640 GPU im looking at getting this for a upgrade AMD Athlon II X4 640 ADX640WFK42GM 3.0GHz quadcore can get it and heatsink fan for 50 bucks would it help my system out i also plan to up the ram to 8 gigs but can go up to 16 i have windows 7 64bit version or would this be better AMD Phenom II X4 965 3.4 GHz Quad-Core