I am using 3/4" rubber out of the HF compressor. It then attached to 1/2" copper right at the wall. I'm only using 1 tool at a time so no problems with 1/2" for me. Plus it's just going around 2 walls of the garage.
I'm just using your standard plumbing solder, and it's doing just fine at 165 PSI, although I do have it dialed down to 140 after a couple turns on the wall. And this is type M.