Calico trailers, sundowner, featherlite and many others will make you a mini horse trailer to your own specifications. I know someone who bought a 5 horse slant built for minis for less than 6,000 new. That was with trailer brakes, custom paint, custom fenders, slide windows with aluminum bars and bug screens. Plus many extras. Instead of buying one of the u haul type trailers that by the time you are done with redoing it would cost just as much, you can order a 2 or 3 horse load for less than 2,000 custom made to your needs and wants.
You know how to make a miniature horse even smaller? Leave them in the dryer a little longer!
"Don't ever regret something that once made you smile"