i wouldnt get any of them, ide get an opteron 148 and overclock to 3GHz , but that depends on what motherboard your using so which one are u going to use?
I agree with gaming_freak. Check the signature, and it has plenty of headroom. 47 Celsius under load right now, so even with the stock cooler I'm running fine and still could easily get it to at least 2.6 GHz on stock too.
u should try to get a lot higher than that jamxx, i would try to get to 2.8GHz right away from what ive heard about that cpu, just make sure the memory divider is set and u raise the voltage and u should have no problems