Unfortunately with air suspension, there are no real "kits" unless they are bolt on's, which I would NEVER recommend to anyone. A real air suspension setup is installed with welds on everything possible, and consists of parts you order separately for the best performance of the system.
You need to be more specific with what problems he is experiencing in order for me to help you out.
You need to be more specific with what problems he is experiencing in order for me to help you out.