The Air Leveling sytem came on the fullsize cars from the factory and I woeked on lots of them - the pumps failed after a couple years. I don't ever remember seeing one on a Camaro.
The system was sold over the counter by the dealership and we put several on station wagons for people who towed trailers. It was a popular item for a couple of years.
I did install one kit on a El Camino and I don't see why you couldn't have installed them on a Camaro, but I don't think they were ever a "Factory" option.
We got all our spare parts from the local Cadillac dealer. I think this system was standard on some models for Cad.