Here's a link to copper.org
tables for type M pipe. 3/4 " at 150 deg F. holds 346 psi working pressure. Actual burst tables show 4700 psi (wow). And the price has come down some lately, $15 for 10 ft. of type M.
Solder I'll use is 95-5 tin-antimony. I agree with oldred for his listed reasons, my decision on copper was partly from his posts here. I think you guys will find his experience is very valuable if you read his many detailed posts on air related topics. Thanks for the clarification on why not to lower pressure cutoff oldred, the machine/paint shop here did that on theirs and recommended it to me (not that I was going to). Your explanation makes sense.
I have a pretty good idea on the airlines, I've done a couple before with downward slope, leg coming off the top and drains at low points. Just wanted to know if the Sharpe's showed a max on them. Sounds like it'll work. Maybe the Jet would too, although I noticed tonight it says 150 psi
max on the unit, could be outlet though as that's what the max gauge reading is. The globe on it is glass, if there's any chance of it blowing not worth it as I have 2 little boys who come to the garage often. I just don't want to buy another that can't handle the pressure (sounds like me in a job I had once