a quiet prescott.... that's like an oxymoron. But, if you must try, then I would suggest the new lowflow air flow dual HW stealth GTS radiator and two Yate Loon fans. I have a Nexus on the single version and it is plenty strong to provide enough air flow. You should get an eheim modified 1046 (i.e. HPPS innovatek or aqua) or a small Laing. I run a fanless water system, but that would be impossible with a prescott.
Honestly, if you want quiet, it would be cheaper and easier to sell Prescott and get a low end Core 2 and use an efficient air cooled heatsink. You will drop 200-300 on a QUIET water cooling system for prescott. In the long run switching to Core 2, this is a better investment than WC in the living room. Better performance from the Core 2, and the extended life of the system and lower energy costs will pay for itself.