You can buy the Rapid Air system at Northern Tool. If you don't have one close by, you can order it online. It's what I bought for my garage after mulling over copper. Copper was more expensive for how I wanted to lay out my lines, plus, I have no experience silver soldering pipes and it's hard to get my brother in law nailed down to do it. I never considered black iron because of rust, and didn't consider galvanized because a friend of mine used it and has always had to deal with the pipe flaking off little pieces of galvanize and clogging filters/regulators. Whatever type of pipe you use, turn your tees for your drops up, instead of down. Moisture flows in the bottom of your long runs, so if you slope it slightly down towards the far end, and turn the tees up, the moisture will travel to the end where you can purge it with a gate valve below your connection. I will admit that before my garage was built, and I worked in my basement, I had my Sears rattle around in the floor portable compressor over in the corner, and a short run of PVC ran along the floor joists above, and terminated by my work bench. I was VERY fortunate that it never 'sploded and killed me! If it had been hooked to a serious air compressor like my Quincy in the garage....KABOOMYOW! :eek: