I would look at a used 1-ton SRW 4x4 truck, something about 8 years old which should run about $15-$20k depending if you go diesel or not. Could go older and stay gas yet still get a very decent truck for $10k.
Then go with a 10 year old camper with non-slide in the 8-9' range. Old enough you won't worry about getting it messy from the fishing, but new enough to give reliable service. This should run in the $5-$8k.
So for about $20k you could get truck and camper that will do what you want.
On the other extreme, $47k for new Ram DRW 4x4 Diesel no-thrills and then throw another $45k for a nice new 11' dry bath camper plus another $2k for hitch to tow the boat.
