Your numbers aren't adding up (dollars and tow rating).
People get nervous towing when they try to overload the tow vehicle. If you get a capable tow vehicle towing bigger is not as intimidating but you lose MPG.
You aren't going to be able to buy a new dodge 1/2ton diesel and camper for $30k. If you get an extended cab, you probably can't get the pickup for that price.
If you go with a small popup, you can probably just stay with your current minivan. (key: SMALL popup).
Once you go hardsided, you are probably up in the 4000lb range and a capable truck won't get good MPG.
Of course, it might be good to have you tell us what you think is good MPG both towing and not towing.
