I purchased the Thermaltake CLP0025 HSF unit for a P4 3.2 about two weeks ago. I am very satisfied with the purchase. My CPU temps have lowered 12C with no other fans running. The fan runs at about 1800 RPM (with an auto fan controlling software- 2500RPM without) which makes for a very quiet unit and that was the main reason I bought it.
It is a very LARGE unit, quite attractive with a windowed case, relatively easy to install (Motherboard must be removed for installilation) and the instructions were pretty straight forward.
I got mine at Newegg for $43.99 total. The priced raised the next day but I would purchase another one at the newer price.
http://www.newegg.com/app/ViewProduc...106-043&depa=0