Originally posted by: PliotronX
Check out the Thermalright ALX-800 w/Zalman 92mm fan (the heatsink is designed for 80mm, but 92mm fits when you have the clips in the sink set for 38mm thick and stick a 92x25mm fan in rotated 45 degrees). Other good ones to look out for are the ThermalTake Silent Boost and Vantec Aerocool.
Originally posted by: Cheetah8799
I just upgraded to a SLK 900a. Very good heatsink. May be above your budget, but check around for used. Zalman makes some nice quiet ones as well. Folks are OCing similar cpus with the 7000alcu model.