Well after some review, I have brought the thinking from a 6x12 down to maybe a 5x8. A little lighter and more compact...the whole point of getting out on the road is to enjoy the road and wide open spaces, not being stuffed in a trailer. Though I don't have it fully planned at the moment I will and then on to purchasing the trailer, I think I might go with HF seems to be the old stand by. I can't say there is a TON of information available on the subject of Shepherds Wagons, but I am getting the general idea...I will have to post my thoughts via google sketchup at a later time of course. Though below is a picture of some inspiration from
http://www.storylinetrains.com/shep.html
Tiki Dude...thanks for your link, after seeing your houseboat I am almost sold on building one of those...quick question on it, could you in theory build on a pontoon base?
Steve...I can't find any information on laminated walls, got any direction for me...although what I have planned might not have walls really...but I still want to read bout them.