That would probably require a WIDE LOAD certificate.
On my "dream" DIY TT build, I would have a 2"-4" overhang with a custom made drip edge/flashin that directs runoff on to the face of the siding. Not sure about actual gutters (likely overflow and would require regular cleaning), but a reasonably pitched/barrel roof with fiberglass or aluminum. No rubber roof. Epoxy resin does not like UV, so paint is required.