I read a while ago that the Intel reference design was one of the best soultions for noise and cooling, but I don't know where you can get one. It was a bent-fin extrusion with a copper plug up the middle. The fins were curved in such a way as to hit the fan blades at right angles all the way out, to reduce noise. Oh, wait. <A HREF="http://www.coldconcept.com/product_info.php/products_id/28/osCsid/a83722ca65bc891f409a0deb5add28fc" target="_new">Here it is.</A> This is the first search result for <i>sunflower p4 cooler</i> from Dogpile, so they're probably available all over the place.
That said, anything from Zalman <i>will</i> be quieter, since that's all they do.
<font color=blue>Learn from the mistakes of others. You won't live long enough to make them all yourself.</font color=blue><font color=green>
<i>Canadian Flight Safety periodical, ~1987</i></font color=green>