As a conservative buyer, I want to know if Thermalright Ultima-90i is enough for cooling i7-965. I'm not going to OC the CPU. My Case is HAF-932 with default case fans.
Since you've got the space, I'd go with a 120mm cooler. A Xigmatek HDT-S1283 is a great cooler - it would do a better job, for cheaper. You might need to buy the retention bracket to fit over that socket.
If you aren't going to OC, you don't need to buy an aftermarket cooler, but buying one may increase the lifespan of the CPU a little. The Thermalright will definitely be better than the stock HSF, and will keep your temps nice and low. Make sure you buy the Thermalright LGA 1366 bolt through kit for it...although once you factor in that it might just be cheaper to buy a different cooler, like this one (first rate cooler btw, and at a great price): http://www.newegg.com/Product/Product.aspx?Item=N82E16835185093&Tpk=scythe%20mugen%202