Many states (Michigan is one) will allow you to pull a boat behind a 5th wheel trailer so long as you don't go over the maximum allowed total vehicle length.. I can look up the michigan law ifyou wish... Kind of scarey when one passes you but it's legal
If you trailer is a standard trailer (not a 5th wheel) then a "Slide off" rack might work... This is basically the ramps you see cars parked on at dealers when they want to show off one car alongside the road. Extend-a-ramps let the trailer go all the way to the ground, I'd suggest a cross bar with a standard trailer hitch at the front, along with the above suggested winch of course. YOu would winch it up, (3rd rail for the caster wheel) hook it to the ball strap down the tires (standard tire strap a-la U-haul auto trailer) and be good to go
Still. I would worry with that much weight on top of my truck, even an f-350 Dualy.. Now an F-350 Custom 10,000 lb GVW,,, Perhaps, but not a pick up