Definitely a market for selling your existing appliances, fixtures, and cabinetry if it's still in good order. You could start by posting it here, there are always other Airstreamers looking for stuff.
As for building your own cabinetry, I'd continue to search the forums. Some people use the lighter softwoods for building frames, and use thin plywood over that for the rest of the carcass. There are also some people who have used aluminum to create the framing with plywood or other materials for the carcass.
It sounds like you are considering a complete renovation, in which case I would highly recommend reading through the "Major Renovations" threads. Some of them are lengthy, but they are absolutely full of detailed explanations and innovative ideas.
http://www.airforums.com/forums/f44/...ons-35399.html
Good luck!
-Marcus