You can do that on air, get a True 120. Go find reviews on the Ultra petleir cooler and see what it's cooling limits actually are. I'd bet it's lower then or @ the same as the True 120. Difference is, pelts burn a good deal of eneragy whereas the aircooler just burns what ever the fan does.....

Asetek? It's like buying the K-mart brand running shoes instead of a decent Nike, Soucomy or whatever. Actually it's worse, because there are far better options out there then that. At the least get a Switftech set-up. They do sell complete kits, besides one's you can put together yourself and their gear is excellent value. But personally, for 4ghz.....a True 120 and many other decent heatsink/fans will work fine and will be a whole lot easier on you.