I recommend the zalman 9500 LED or the 9700. The 9700 is newer and a littler bit bigger. If you read reviews around the web, you'll find these two are top picks for any OC project. Even tom's reviews on different mobos, cpu's and such use the zalman. That's gonna be your best bet. I'm not trying to bash that other guy, but if you purchase cheap parts, you often times get "cheap" results. And since this is something thats going to be keeping your cpu from burning itself into the ground... well, I'd rather spend the money and get a really nice hsf. Otherwise, if your like other people with money to spend (but I figured not, since your getting the e6400), then there's always the monsoon II. It's a peltier of sorts, and has very high recommendations from the people that use them. I think the last I saw one, was priced at $140. Oh, the zalmans can run you around $50-65, I think. Go to newegg.com and see what they are priced at.