For a truck camper you would be hard pressed to find one that will work within the factory specs on a half ton. I would suggest either a 3/4 ton or a 1 ton. A 1 ton isn't much more expensive than a 3/4 ton and usually provides you with higher payload, which you will need for a truck camper.
All your gear will count 100% against your payload, as opposed to a 5er with 25% or a travel trailer with about 13%. All your food, clothes, guests, dogs, water, blankets, pillows, plates, firewood, chairs, etc.
A half ton MIGHT have just enough payload to haul a dry truck camper... but you will need some supplies when you go, which will likely put you over the weight limits of a half ton.
