I suspect a gas chassis isn't up for the job. 1/3 of my coach hangs behind the rear axle and adding over 1000 pounds to the rear might cause drivability issues concerning weight distribution between the front and read axle. You'll need to research a choosen coach very carefully in particular available weight capacity of the rear axle. Some will come off the builder's line with less than 1500 pounds of usable capacity split between both axles.
As mentioned the framing on the back end might not be up for the task also and will possibly require maybe boxing or other modification.
A better choice might be a swivel wheel trailer such as
ONE OF THESE.