Do a search of Ars for that Zalman model. I've never played with that one and my own rig is AMD based so I don't much pay attention to the threads on P4 cooling. I know quite a few people are happy with their Athlon cooler though.
You should also consider the Alpha:
http://www.newegg.com/app/viewProduct.asp?description=35-112-003&depa=1
And the Thermalright:
http://www.newegg.com/app/viewProduct.asp?description=35-109-009&depa=1
Once you get the CPU cooler replaced and the system fans in check, listen to the results. If it's still too loud, pull the side panel off and try to localise the noise. If you have a sound meter laying about from your HT tune up, that might help you identify the source if it's too loud to be specific. A high pitch noise will likely be the Video card. ATi has used relatively good fans on their latest models but it still may be bothersome to you. I'd recommend a passive solution with something like the 9000 as it's not a terribly hot card to begin with. Beyond that, you'll have to consider more creative approaches.