For moisture control I have a few runs of black pipe close to the tank that go up a down vertically with drains on each then a water trap,etc. I really only have one drop (it's a normal 2 car garage, I can reach halfway down the driveway with my hose). In the summer in Georgia, I have moisture issues - right now its fine. We have close to 100% humidity everyday in the summer.
The two compressors idea is interesting. Wish I'd thought of that sooner :P use auxiliary tank, etc. Would have saved me some money... :P I wonder how often you'd have to replace those, though. Laszlo, didn't your husky lock up?