Hi Louie,
Welcome to the Forum, glad to have you aboard.
I have the Hondas, love them and would recommend them to anyone. Others may be super, but I don't know about them. I would stick with gas units, Propane drops the power on the generators.
I know the Dometic brand and think they are great, good thing about a common brand like that is most dealers carry them in case there is a problem. I have two 15K units, when you get one, get a 15k, a few more dollars (Very few) and you won't regret getting the extra cooling.
I have the stackable Maytag's, my wife, Sue loves them, she can knock out a few loads in a short time and we can explore the area. Big
loads are no problems with them. Many folks have the combo units and are happy as clams.
I have a 3/4 ton Super Duty, it is fine for my 3400RL, a pulling machine. I went to a spring shop and had them install a overload spring, money well spent. I have had air bags and they were great as well, if I had to make a choice, it would go with the springs. your
35,000 miles is low mileage for a Diesel I wouldn't worry about that. I would suggest buying an extended warrantee for it, keeps expensive surprises on the road down to a minimum.
I bought an air suspension Husky/Reece slider for my short-bed really like it, an air suspension is really nice to have. Don't know if you have the anti-chuck 5th wheel, but you need some sort for a comfy pull.
From one swabby to another thanks for your service.
Brown-water Navy; Nam.
Ozz