I am having trouble deciding on which CPU to get. I am wanting to get either the AMD Athalon 64 x2 4200 or the AMD Opteron 165 Denmark. I dont know if I plan on overclocking yet. Which one is a better cpu? Also its going to be used on a DFI LANPARTY UT nF4 Ultra-D Socket 939 NVIDIA nForce4 Ultra ATX AMD Motherboard.