I went with the noctua. 12.8 dba (on low) is a lot quieter than most of the other stuff out there. my case is rated at around 20 dba. I'll let you know if it fits. If not I think I'll spring for the corsair water cooler thing. From what I saw, the 7 inches SHOULD be enough to put in the cooler plus extra clearance for the mobo, chip, mobo tray etc etc.
I can't see a reason to overclock at the moment. I plan on doing digital recording and hopefully some live sound editing and synthesis. I don't know if it's necessary to overclock for that, and if it is I'll cross that bridge when I get to it (and I think the noctua will suffice.)
Anything is better than the jet-engine-like computer I have now. Thanks for the help!