The Lincoln navigators had air ride, but also had a very expensive system (atleast through the OEM), because when they failed, people often just didnt replace/repair.
Its not really a complex system, or atleast doesnt Have to be. It can be as simple as a belt driven compressor, clutch, 30 ft of hose, and air bags; or it can be as complex as matching air pressure to terrian and speed...
I have considered adding them to my Ram, but just manual bags, and did some breif searching for larger, stronger brake systems that are direct replacements.