Does anyone use removable hard drives (mobile racks, HD cases)? I'm trying to decide if I need one with or without internal fans. The one I'm looking at has an aluminum body. I'll be using a Western Digital 20GB 7200rpm hard drive with it. I've heard stories that overheating in one can kill a hard drive, but I don't want the extra fan noise if it's not necessary. I'm planning to have them in my desktop PC and also inside my arcade cabinets.