That Delta is awesome. It sounds like a jet engine when at full speed, but it volt mods wonderfully. Trust me...I have it cooling my CPU (I can get you a pic later) and it's connected through my fan controller. Now it's no louder than my case fans.
Zalman fans are the best, the case ones, I use the ThermalTake Xseries everywhere, 92CFM, something like that, I might look into buying that first fan for my CPU..