To the OP's question, Sioux or Chicago Pneumatic US made drills seem to the the class of the crowd. The Yard Store used to have used drills, but they only have right angle ones these days. I've never had enough air to run a pneumatic, but I've used them on other people's projects, and they are nice. Lighter than a powerful rechargeable, and smaller.
But having said that, I use several HF "Bauer" driver drills around the hangar. The cheapest HF CORDED drill also spins up to 3000 RPM, and I have an earlier single speed version that drills rivet holes as neatly as any pneumatic.
http://www.harborfreight.com/power-tool ... 58528.html Metabo makes a high speed cordless drill specifically for sheet metal work, up to 4000 RPM, but they are frightfully expensive (over $600 with a charger and battery), albeit probably not as much as a big air compressor and a quality air drill.