I went with something like this. http://www.northerntool.com/shop/too...5476_200415476
I can't remember the brand name, but it's safer than PVC yet relatively cheap compared to copper, and flexible to run around the shop. If I was planning on using my big compressor regularly(i.e. more than once in a blue moon) I'd go with the copper setup.
I just got this stuff with visions of maybe painting the truck myself when the it is ready!