Currently we have assembled a Harbor Freight 1720 Lb. Capacity Super Duty Utility Trailer, 48" x 96" Haul-Master - item#94564.
No frame modifications, yet.
Currently thinking boxy style stretched from 4x8 to 60-66" length of 8-9', overall height of 6feet, no change in wheel track.
Somewhat like the larger trailers from http://uev.com.au
Specifically this model, but smaller.