Treeview wrote:The soft sides on trailers aren't cotton canvas, they're vinyl which is very easy to add lettering and graphics.
YOu're the most familiar with what you want of course. It seems to me that a hard sided trailer would have to be larger and heavier. Along with harder to load/unload. I think that a scale model mockup would help. Popsicle sticks and kayaks cut out of foam would help.
But that's just me...
Tom
I still call vinyl flooring linoleum

If hard sided is what's wanted OP should check out snowmobile enclosed trailers. See if a dealer will let you "test drive" it for how a big lightly loaded trailer handles.