I went with this company. Their tutorials and system design help were awesome. http://www.radiantcompany.com/
If you want to see the finished product, check out my webshots album. "][/URL]
Good luck on the build, the floor heating was the easiest part for me.
I don't know the answer to Jey's question but I think for bluesman, I'm no plumber mind you but my brother is, I think I'd put in a holding tank and lift pump at your shop and plumb that into your existing septic tank up the hill. I have even seen some ads in the back of home-improvement mags...
I used to do gas plumbing here in Wa St. I used to press it to 30# with air and then soap the joints. The inspectors usually want to see a pressure drop test but like Hoosier said, the soap tells you the best.
You can get a test gage assembly that threads onto a pipe and has a tire valve on the...