You can call Kent over at Lothringer Engineering. He raced and prepped a Giese 10 car with air shocks years ago. I seem to remember there was something about the shocks that wasn't ideal but can't remember what it was. The car was fast for its time though so it worked to some extent.
I just picked up an old Baja Bug pre-runner and it has Giese air shocks on it. The rears are 48" extended and the shafts are massive about an inch! the front shocks seam pretty beefy as well pulling them off to update the car but would like to learn a little more about them.