I don't get not considering a soft side or pop up (with good insulation and a forced air furnace) when 1/3 to 1/2 of your camp party is sleeping in a tent on the ground??? Just sayin!!
That camper listed is going to come in at about 3400-3500 pounds with water and camp gear loaded. Add another 200+ pounds of tongue weight for the boat ? and you're getting close to 4000 lbs of load. I'm no weight police but I'd look at your 2500HD closer. If you have to purchase the truck also, why not look at 3500/350 class trucks?