Although your trailer manufacturer will probably void the warranty on your trailer, I would convert the hitch on the trailer from a kingpin to a gooseneck.
But you can't just simply install a gooseneck hitch on the trailer. The gooseneck will add a lot more twisting and bending force to the pin box and the frame up under the overhang of the trailer, so you have to have a good welding shop reinforce that area by adding a lot of junk iron. To access that area, if underneith your overhang is covered up with fiberglass or aluminum skin, then you have to remove the skin before you do the welding.
The owner of the local welding shop I use converted his 5er RV trailer to a gooseneck several years ago. He's drug that trailer thousands of miles with no problem. But the area under the overhang is reinforced with a lot of iron welded in.
Colibert makes the most popular gooseneck conversion kit. Click on the following link to see several brands of gooseneck converters, including the Colibert brand:
The Hitch Corner sells gooseneck to 5th wheel hitch adapters
Note that most brands of gooseneck conversion kits caution you about the additional leverage the gooseneck conversion has, but most don't mention the obvious fix: weld in a lot of junk iron to reinforce the frame of the trailer under the overhang, and to heck with the trailer waranty.
