A little off topic, but I've just put together a spare system for our studio and used a socket 939 3700+ that overclocked to 2650MHz without even trying.
At that speed and a Thermaltake Silent Boost 8 the temperatures never got over 55deg C with 9 hours of Prime95 (ambient was low 20's). That's hardly a high cost (about US$15 I guess) HSF, so it could be an option at a fraction of the more prestigous models usually suggested.
It's a bit quieter than the stock - I can't hear it over the generic PSU fan.