If you can, go into several different manufacturers and floorplans. You will quickly find out if you prefer a mid or rear bathroom layout. You said that you're mostly going to be in a campground so the holding tank sizes aren't that important to you. Since you plan on towing a boat and it's just you and man's best friend in the camper, I'm thinking a 8'6" to 9' would be enough. Do you care if the kitchen has a single or double sink? I see that you have a Dodge 2500, in my opinion the addition of SuperSprings provides a nice suspension aid and helps reduce sway.