Have you tried calling Thor's customer service?
I would think they would be in the best position to help, although I'm not sure if they will or not.
I called them wanting electrical and plumbing schematics for my new coach and struck out.
I have read that others have had better luck getting at least basic diagrams.
Barring that, I would think that it would be fairly straight forward to route the plumbing. I don't believe that there is anything very unique about it beyond running cold water to all fixtures, and running hot water lines to the faucets.
a low point drain
and a bypass header around the water heater
Are you planning to use pex or something else?