Boring, they likely won't use PVC due to all the joints due to the pulling pressure put on the pipe. Joints are another reason to stay away from PVC. Best bet is HDPE, it can absorb pressure surges better than PVC. That is the standard now. PEX can work too, but is less available in the 300' roll length necessary to do the pull without fusing a joint. Copper is great if your water is not corrosive. I have seen copper services with pinholes due to corrosion. An advantage to copper though, besides it's use as an electrical ground, is the ability to use a welder to thaw a frozen pipe. My 46 year old service is 1" plastic (HDPE) from the curb box to the house and copper from the main (across two streets) to the curb box. Worst: galvanized.
I don't believe the electrical code allows just the water service to be used as the ground, you must have ground rod(s), bonded to your metallic plumbing pipes.