I went with a 12 foot aluminum Discovery cargo trailer with supports on 16” centers for strength and so I can stand up and back out the back ramp door and have the advantage of large wheels and side door. Used multiguides and rubber pads thru out and tows like a dream. You can pack gear in the back too plenty of room. I couldn’t find a 1 up snowmobile trailer anywhere new or used so did my own thing because trailer dealers weren’t interested in selling 1 up enclosed trailer’s either. I can send pictures if your are interested in seeing what I did.
