any suggestions?

I used all copper pipe in my shop. It has never blown out and it's easy to solder together. I have no idea if it could be unsafe to breath air from it. I'm not certain who you ask that question to. I know galvanized metal gives off dangerous fumes if you weld with it. I think pvc would hold up and is probably inert.

I think copper would be a bad idea as it will go green on the inside and i dont think that **** would be good to breath wouldnt stainless steal be cheaper

I guess thats right about the copper. I never bought stainless so I don't know about price. What I liked about copper was I could easily possition a connector and solder it. I had trouble with black steel before that when I screwed it tiogether tight, the connection was faceing the wall. But I don't have to breath that air. I have seen flexible plastic in homes for air ducts. If it can take the preasure it might be a good idea and cheap.

Use black pipe. Run the line downhill (from source) with pipe saddle hangers found at any decent plumbing supply. There is a ceiling bracket, all thread drop, & saddle fitting. It's cheap, easy, & flexable. Put plenty of t's on the lines, so as to allow later line additions. Use a t's instead of coupler fittings, with a plug in extra hole. Using t's is cheap insurance over the cost of a coupler, & the risk of having to tear apart later to add a run. Put condensate filter at end of runs, prior to coupler outlets, at a height that's reasonable to get to. This is the industry standard for shop air lines. It's cheap, & it works.
Galvanized pipe is only galvanized on the outside, which simply doesn't help anything. Copper works, but is very expensive these days. Black pipe will last a life time, which is probably long enough for most of us.
Joe