E 350 Cutaway Chassis - custom built motorhome garage

[MarkScott]

I'm glad to see the board alive again. I want to construct a custom box for my 2000 Ford E350 cutaway chassis. The WB=158, currently has a 14' Penske FRP box. I want to stretch the chassis to accomodate a 18' to 20' box for a motorhome/garage set up. At 20', I was thinking 8' of living space and 14' of garage. I need to carry 3 race bikes, tools, fuel, water etc. I would also like to build it with a overhang over the cab, although I would like to taper the overhang, much like the larger motorhomes. I am thinking 2" x 3" tubing for floor supports and 1.5" square tubing for walls.Any thoughts on who I can buy the corner caps, roofing, trim angles and material like that from? Please share your thoughts, since I am uninterested in todays class C options or converting a supreme of morgan box for this conversion. Thanks, Mark