Ok, so I've recently purchased a couple of external enclosures; one for one 80gig EIDE WD and one for one 160gig SATA WD. Now, since I want to use these on a constant basis (as they will end up storing my movies, music, games) I need the drives to cool better than they do in the aluminum enclosure that came with the PCB that I was after.

Right now, I've got my idea for mounting these drives, but I have two things that I need to work out;

1; what to use as the enclosure (note that a PSU will need to fit into it to power whatever coolant I use)
2; should I use liquid coolant, or air coolant? If liquid, what liquid should I use, and what equipment will I need?

Anyone have any suggestions/tips?

You could make a really snazzy custom enclosure for pretty cheap using plexi glass. There's just no need for liquid cooling, a 120mm intake and a 120mm exhaust should be plenty as long as you design the housing correctly. Just make sure to leave alot of room in between the two drives. If you have an old case that you wouldn't mind wrecking, a salvaged HD cage makes building enclosures alot easier.