I like buying cooling stuff from these places:

http://www.performance-pcs.com/catal...7a8b228b65266a

http://www.svc.com/775-cpu-cooler.html

http://www.sidewindercomputers.com/home.html


Get one with a back plate that screws in, not cliped in. They work far far better. Taking the mobo out of the case isn't all that hard and is well worth the effort.