They also showed me coils of copper tubing - in K and L category. What
is the difference in K and L copper tubing? It is more expensive than
CPVC - but you would have only one coupling overhead - not like the CPVC.

They also showed me union joints that join CPVC and copper.

I appreciate comments on this job.

Of the copper, one it thicker than the other. Don't remember offhand which
is the thicker, but should be the one that costs the most.

Also look at the Plex (however it is spelled) type of pipe. It had a bad
reputation in the past, but it was not the pipe but the couplings. I just
had my house replumbed from copper a couple of years ago.