I did some serious digging into this a while back. Basically with the high prices of Broncos now and the rarity of these campers, you are going to pay big money ($12k-$15k) for a camper Bronco that was built in the 70s or early 80s and not be in very good condition. It's going to need a lot of work usually, not to mention the Bronco will too. I searched high and low and sent several emails to the companies making them now to see about getting a new one built on the back of my Bronco. That will run about $10k and I highly recommend All Terrain Campers (ATC) over Phoenix Pop Up (asking $17k), the only two companies I found that will make one with ATC having a better reputation. Four Wheel Campers, the original makers of the most common Bronco camper, quit a few years ago due to losing money on them.
It almost makes more sense to purchase a new pop up camper to pull behind your Bronco for the same price. There are several other options where your money could go further. I found some other members on here with them and they love them and enjoy them with their family, the reason I wanted to get one.