You already have much to consider. Just my $0.02. I do think it's a good idea to look hard at the 250/2500 series trucks. I towed our 6800 pound (loaded for camping) trailer with our F150 for 5 years. We also live in Ohio, and towed that combo to New England numerous times, South Dakota, Tennessee, and other places in between. We had no problems during those tows. After running the truck/trailer over a CAT scales, however, I found that I was over the rear axle rating by almost 500 pounds. As we are nearing retirement age, and hope to do even longer trips, I was nervous about that. Additionally, during a truck hitch inspection, I found that the receiver box was starting to split out, and had to have it welded. We did upgrade to an F250 a few months ago, and I appreciate the additional peace of mind. Another thing to consider: if you rent a TT or 5er, what about the hitch? Maybe you addressed this and I missed it. With my current F250, I can tow this trailer without a weight distribution hitch (I don't tow without it, as I already had it, and use it, but the truck specs allow it). If the truck you buy requires a WD hitch for the weight of trailer you are renting, someone will have to supply and set that up. Same for a 5th wheel.
