Is there really a 1/2 ton towable fifth wheel?

Every half ton will tow a 5th wheel. You might be doing a wheelie but the truck will tow it. Only some will be within specs for payload and most wouldn't be. Manufacturers like to play on words. "Ultra-light" means it's 50 pounds lighter than the standard "Light" model. Manufacturers and dealers don't want to tell you that. Many don't have a clue either. I went to an RV show recently where the owner of a dealership argued with me about payload. He kept telling me that payload was the "Stuff" you put in the bed of the truck and nothing else. I said, "So the weight of all passengers and coolers and anything else inside the truck and the tongue weight of the camper don't matter?" He said. "I just told you that payload is the stuff in the bed of your truck". What a MORON!