Great project.
Insulation:
Consider the sound transmission properties of different insulation methods to reduce outside noise.
Simple math to calculate weight distribution of fixed equipment carried between the axles: Divide the distance of the center of gravity of the equipment to the front axle by the wheelbase. The result is the fraction of the weight of the equipment that will transfer to the rear axle.
example: water tank full weighs 1000 lbs. Wheelbase is 200 inches. Tank cg is 150 inches from front axle. 150/200 = .75 x 1000 lbs = 750lbs rear and 250 lbs front.
I have a spreadsheet somewheres that will cipher loads including behind the rear axle (which take weight off the front axle) ... it's misplaced at the moment...:h
