I have narrowed down my body selection to 2 now. The Aerocell is a 17" box, yet only 16' inside and 7'6 wide. I really like the look of this style.
My other possible choice is an all aluminum ITB commercial truck body. It will be just over 17' long and a full 8' wide inside. This is almost the exact truck body here. Just add underbody boxes.
I also have a specific floorplan for each. Since I only want to build this once, I was thinking of making a full size mock up of each out of cardboard in the shop. I dunno...seems a bit overkill...
Each one has its pros and cons. Looks, strength, durability, cost, function, ease of build, ease of maintenance...and many other considerations.
I'm open for comments/suggestions/advice.