This dude is on the Escapee forum as a member and RV'er, and built his own. But he also does it for a living. He has pointed out he'll do partial builds......
Custom Motorhomes, Motorcoaches, Toterhomes, Truck Sleepers, and Enclosed Trailers :: Transport Designs
Here's his personal blog:
http://www.carefreeway.com/
A link to my yappin' over there....
http://www.rvnetwork.com/index.php?showtopic=98328&st=0