I'm assuming it makes a difference where you live weather wise. All I know about is where I live. Southern California. I'd say 99% of all new installs here on residential are PVC pipe. The size of the pipe depends. I'll let your installer figure that out. Maybe you should tell us where you live.
I live in Missouri. I have two quotes from two installers one for $4,200 and one for $3,100 - Big difference. The $3,100 uses Hunter equipment with the 1" diameter PVC pipe with the poly pipe, clamps, and compression fitting.
The second quote for $4,200 the installer uses Rain Bird equipment. He uses 1" diameter PVC pipe and uses PVC connectors and PVC cement. He said he will NOT use poly pipe, clamps, and compression fitting.
I want to know is there a big difference between the two quotes? Does it matter if I go with the cheaper quote since they use poly pipe, clamps, and compression fitting? Since the first quote is so high it looks like the poly pipe, clamps, and compression fitting is a bad thing or he's trying to make a lot of money.