been seeing some new fifth wheel camper trailers lately, forget the name right now but they are ultra luxurious and come with big pimpin' 22 inch chrome wheels. Looked pretty sexy, but I couldn't help but wonder how they'd tow. Couldn't be that bad or they probably wouldn't use them. Initially I thought the owner put them on himself on the first one I saw, but when I stopped at the RV dealer and saw a line of them, all with 22s. I know when I used to have them on my wifes Avalanche 1500, it handled well, however they would chase cracks and uneven portions of the road. I'd think I'd not like to tow a trailer with big wheels on it, but really the 20s aren't that big and in my experience they have equal or better ratings to stock.
I think that truck oughta be able to haul that boat ok. Make sure the brakes work and the bearings and tires are in good shape (boat trailers always have bearing problems). The aerodynamics of a boat work in your favor. And they're always a lot lighter than they look. NADA figure should include eerything but the trailer weight, like a GVWR. Counts passengers and gear and fuel. I think.