I have owned 3 enclosed trailers. First was a 6X12 cargo ramp built by Haulmark, not a good trailer, screws started coming out everywhere, it leaked just not very good. Second was a 6X10 with barn doors, too small and I hated the barn doors but it was built better and I will explain that. My current trailer is a 6X12 with ramp door, it has been OK but again not the best build quality. I had a local trailer manufacturer build it as they had a good reputation but again, it has a few issues but nothing major. Things like screws backing out because they were not put in straight in the first place, a common theme on my first trailer. Also my first trailer had the framing on 24" centers, never do that, get 16" centers everywhere. Ramp versus barn doors, ramp for me. It also allows me to move a lawn mower if needed or other things I need moved the ramp door is much more useful. In the end, I would advise a 6X12 with a ramp door and 16" centers for framing, also get interior lights, jacks, vents on the side that open and close, avoid the roof vents, LED exterior lights and think about color, I would avoid the darker colors and if at all possible keep indoors or at least under some sort of covered/roofed area while not in use. Good luck.