Goose neck, 5th wheel connection, Long bed, short bed truck

Just cut all the other conjecture out and listen to this:
You need a DRW 1 ton...PERIOD
This means you also need a long bed...cause DRW short beds just look dumb.
Then just pick whatever hitch you want (but not a GN adapter).
It's an easy problem to solve because of the weight of your proposed rig. If you were going with a substantially smaller rig, then you'd have more options to discuss.