Here's a candidate trailer kit: 5' x 8' aluminum trailer kitI think the perfect trailer for the bolt would probably be about 4 foot wide bed 8 foot long, a flatbed (basically plywood size), tall skinny tires, and as flat as possible above and below, made of aluminum, and have wheel covers ....
Not sure what to make of the 5 x 8 dimension. What material would you use for the floor?
And it's expensive compared to the Harbor Freight steel 4 x 8 trailer kit.