Truck bed is an 80-86 Ford, looks like a 6' bed, but a pair of lights from 87-91 or 92-96 F-150, 250 or 350 should also fit.
If you want to run a single tube from front to rear to use as the trailer coupler mount in front and as a hitch receiver in the rear it should have a 2" X 2" inside measurement for any accessories you want to attach to the rear. If you buy a tube you will have to add the ring and any other hitch items to the back as well as the coupler in the front.
I would attach the new front A to the insides of the truck bed frame, stitch & plug welding it in place and gusset it as well. You could also fab a rear receiver instead of having a tube running the full length, it could mount to the rear of the frame and be up high near the bed floor, you could mount it like a standard bumper or class V hitch making it the rear bumper as well.
The wiring if not cut up too bad, it should be there to run a 7 wire plug especially if the original truck had a tow package. If not get some wire and wire loom and make your own or go to a pick & pull & take a harness off another F series truck. You could wire up the reverse lights to work as well, or change the reverse bulbs (clear to orange) to turn signals so you have separate turn & brake/tail lights. you will also need to wire up electric brakes if you add them & a charging wire for your onboard battery.
Removal of the bed is a good option especially for access & so you don't have to weld upside down. If you plan on adding any water storage tanks poly gas tanks could be used, will mount where the factory tanks were, but cost $$$.
A cap is a good option & if you are going to sleep in it a utility cap is another option, or one with side windows that fully open like a hatch back.
Axel options are whatever you like or can afford. Trailer axe w/ or w/o brakes, a FWD solid rear axel, or what you already have.
Welding? Practice, practice, practice, with scrap metal that you are going to be working with, but you know that from the work you did on the Scout.
I hope some of this helps.