I'd like to replace the stock heatsink and put indivdual cpu coolers, Reason being, I understand that the 120mm fan blows over the sink and keeps it "cool", but, it's still getting to the point of hot where I am not confortable.
So, I need to know what kind of Cpu cooler I can buy... I am a major fan of Thermaltake, Coolermaster, anything with a Copper Core.
Apple designed it to run cool enough under heavy load that the thing doesn't lock up. You're not going to find a direct replacement for the stock heat sink, you'll have to fabricate an adapter plate to fit a PC heat sink. It's really not worth it unless you're going to liquid cooling or something.
You can get quieter fans at newegg or performance-pcs. The cpu fans are loud. Change up with some deep 40mms. A Panaflo low speed 120mm works great in these. They are deep though. They are sometimes called Rexus as Pana sold out, but ppcs still names it right. Enjoy a far quieter mac and cooler performance.