Sounds like fun- we did the same search before we left on our 2 1/2 year "everywhere" trip. I ended up with a Safari, but was really looking for a Globetrotter. The extra two feet in length doesn't make a big difference in parking or weight, and it was what I could find. My search got narrowed down to 1965
model years, because the door was closer to the middle of the body, and the bed in front could be left down most of the time.
Due to a design flaw in the back of the trailer (where the shell connects to the subfloor and frame above the bumper), water gets pulled in and rots out the subfloor under the bath. It happens to all of them, and they either have been repaired, or need to be.
Go with the F150. We pulled ours back and forth over the Rockies (with a full water tank) with a 1990 that has a 5.0. I had a great old '62 Tbird I would have loved to use for the style, but I knew it wouldn't be up to the stress. The long wheelbase makes it all so much more stable.
If it's even remotely questionable, replace the axle. You only have one under there, and it's the thing between you and catastrophic adventure-ending nastiness.
I ended up building a dinette across from the stove and sink, and went with a double-bed gaucho up front. Felt too much like Ricky and Lucy with the twins.
Get a big, big battery, and get rid of the univolt charger. The best places to camp have no hookups, and I'm sure you aren't going on the road to look at the side of someone's Winnebago in an RV park.
There are a lot of people that would be happy to inspect one of your potential candidates for you, and tell you if there is anything that would be a deal breaker.