This is the heatsink i have for my Core i7 920, and it works with socket 775 as well. Its a GREAT heatsink for the money. I can overclock from stock 2.66ghz to 4.0ghz with acceptable temperatures. It uses a screw base, not those piece of crap plastic snap pins that you see on a lot of heatsinks. It comes with 1 120mm fan and provisions to add another 120mm fan onto it. Can't really beat it for the price.
Amazon.com: Cooler Master RR-B10-212P-G1 Hyper 212 Plus 775/1156/1366/AMD/AM2/AM3 Universal Direct Contact Heat-Pipe 120mm Fan CPU Cooler: Electronics