Looking at the last sketch on graph paper, I figure your bed will be 74"?
I think 78" 's the optimum lenght for a comforable teardrop.
Thus, I would make it 100" rather than 96" ( buy 10' sheets of plywood for the sides)
And use 0.125 wall 2or 0.188 wall 2"x3" tubeing for the chassis. (0.250 wall is overkill)
Just my 2 cents worth.
Very cool design!
I llove the doors and hinges.
Good Roads
Brian