Brian,
I am far from a shock expert. I only know so much. I have had the opportunity years ago though to see a fully cutaway version of the Pro Stock Double Adjustabe that Monroe was making. It was made from a clear material for show demo purposes and I was really impressed. I also saw the similar thing in the Bilstien Gas Cushion shock which was different but displayed the same with the clear material shoing all the valves, the fluids etc. Just by moving them rapidly by hand I could see the differences when the gas was introduced by the complex valving system and was again recovered in a separate chamber. The Monroe was a oil operated shock with gas preure introdiced in needed amounts to keep the oil from aeroating. The Bilstien was a Gas Cushion shock that was far different in design.
I think that the shocks that Tom posted the pic of are the Co2 Chamberd Penske Pro Stock style shock, The extra canisters are for a Co2 gas.
IN my opion Roger Lamb is the foremost authority in drag racing shocks and it is similar to what is being called off the shelf double adjustabes that he modifies for serious racing in the top cars. If you buy the best car that Tim McAmis, Jerry Haas, Jerry Bickel, Rick Jones, Don Ness, and others make for the ultimate drag racing class of NHRA Pro Stock, you will get either the Co2 Penske with controller or the Strange or Koni Electronic with controller. Before these two options existed the double adjustabe that Koni, Afco, and Strange sells were the hottest thing available. Like I said before, most of the real serious racers do send their shocks to Roger Lamb for re-calibrating, or they buy shocks from him.
This is my last post on this subject. I have no proof and really don't care if anyone disagrees with what I have written or not. I go by memory in ust about everything I post. So what is in my head can not be proven to anyone.
If anyone really cares to find out more the information is available. Call any of the Pro Stock builders and sk for shock recommendations.
Ed