the biggest boat that would reallisticly be on the back would be about 12500lbs (saw that typo....not 17500) but would like to over engineer to be safe. most of the hauls would be under 10,000lb(load and trailer) though.
welding up a rear frame and hitch to handle the load is no proplem...i think.( have a welder that can do ANYTHING)
gears/axles could be swaped in to handle the rig...right?
disk brakes of coarse.
the trailer is a hitch mount. all six wheels have disks.
saw a pic on this site with a 1 ton pulling a airsream and it got me thinking....