I have a Treg with air. Replacing struts with used has been a mixed bag - 2 worked, 1 didn't last long.
Most recently, I replaced 2 with reconditioned units - 15 months in, no problems. Touch wood.
I go to a guy in Mussaffah - doesn't everybody in AD? - who used to work for the Audi VW dealer. His premises aren't exactly like Ali, but neither are his rates.
Ping me if you need contact info.