And I'd like to see side-mounted heatsinks. Just plates, say (so it'd be easy to have holes for disk mounting) with 1/2" or 3/8" copper tubing soldered (or brazed or silver soldered) in a serpentine shape, avoiding the mount holes. And maybe some rubber blocks with inletted nuts facing out to facilitate mounting in 5 1/4" drive space (not sure about that latter as IMHO if you're not sealing the drives up in some sort of box there's really no reason to water cool.
And, actually, given fairly quiet disks to start with (like the spinpoints as seagate sadly seems to have lost interest in making the quietest drives) and suspension (or other means to isolate seek-induced vibration transmission) and some sort of noise absorbtive material inside the case (or lining the baffle, if you've a baffled case) then IMHO you can have very quiet disks and still be cooling with air.
The challenge comes when you're trying for a very quiet system using SCSI drives. W/C ing very possibly makes sense there...
PS: the forum software keeps changing "o u t w a r d s" (without the spaces to) *****ds. How exactly is this a rude word? PM if you need to explain in a rude way
