The WJ has a tow rating of either 7200 or 7500lbs I can't remember any more, find one with the proper factory tow package and you get a hitch all the wiring, a trans cooler and a power steering cooler, just add a brake controller. My 16' trailer on the first page weighs 1650lbs ready to go and its a very sturdy trailer, its GVWR is 7000lbs so it can roughly carry 5500lbs. You really need the WD hitch though, they usually run around $300 new.... If your looking at just parts or a few odd Willys I would look at dual axle 12' or 14' trailers, wood decks, with at least 1 brake axle, 2 would be best... Maybe find a way to lighten the trailer up. I had 250lbs worth of angle iron under my flat bed just to store the ramps that slid in from the side! I cut all that off and now I just pin my ramps to the trailer, saved alot of weight. I also only used the boards that the Jeep sits on, I removed the 4 center boards that were 16'x10"x1.5", that saved some weigh as well. I easily shaved 300lbs off my trailer, I haven't weighed it since I did all that though.
There is no reason to buy an f350 to tow 4 or 5000 lbs a few times a year and sit for the rest of the time...