Arnott Industry shocks out of florida - I've been dealing with them for almost 20 years and they are great to work with. The have the fancy Cadillac, Denali etc, remanufacters and new shocks and the beat the dealers by a mile ( a fraction of the cost). I know that they are working on the magnetic ride shock solution and will hopefully have something soon. Talked to Robert in their tech support department.
Although they no longer sell direct and sell only through Parts jobbers and online resources, but they will answer your technical questions.
I just replaced the compressor, rear air shocks and front strut assembly with shock on 2011 Chev Suburban LTZ and it rides like new.
