Since my original post I have ordered a Ford Ranger. It has a 7500 lb tow rating, so I will definitely look for a smaller, lighter trailer. I’m still leaning towards a 320, but when the time comes, if I can find a good used Casita for a reasonable price, I might go that way.
Maybe I should have mentioned I have camped with my wife in a 27-foot Airstream, a 35-foot diesel pusher, a MB Sprinter-based class C, and another 27-foot trailer. I’m pretty familiar with the pros and cons of size, and since it’s likely I’ll be traveling by myself, a smaller RV is all I need. After all, my last “camping” was a foam mattress in the back of a pickup truck. Pretty much anything will be a real step up from that.