Before you do anything go to your local Loews or the like and get a book on plumbing. There are so many new types of pipe/tubing on the market you can't imagine.

A book called "Building an Affordable House" by Fernando Pages Ruiz recommends HDP(hight density polyethylene) over PEX for water lines and ABS(acrylonitrile-butadine-styrene) for sewer.