ah - those are called air shocks on this side of the pond.
i am running them.
if you need any fittings - i can get anything and i'd be happy to drop-ship the stuff to you at straight cost.
i am planning on an airbeam. two air bags (like i have in the back).
i see your through rod. did you fab that up? Is it just threaded rod with nylock nuts on the end? any thrust needle bearings?