After considerabke thought, I have decided to base my build on a 4'x10' Cub style. But increasing the width to 5', and am considering making it 5' tall also.
So, my trailer choices have changed. Rather than a HF kit, I am now looking at the NT out so I can go 5'x8'.
So, the question becomes this: If I weld the NT frame, wouksd it be suitable for occasional off pave road excursions? Not four wheel rock crawling, but dirt roads.
If not, I'm sure I can learn to weld and make my own trailer. Probably save some money that way, I want to spend my time on the box.
Besides, I've already found the adapter hubs that I can use on the NT trailer for my rims.