I like to help people. I just wonder how much searching you did on your own prior to asking for help. There are a bazillion build threads on these truck forums that show how they install airbags and tell where they got them from.
Here are some I found in 10 minutes by using the search function.
Lowering the rear thread idea.
Click here There are many projects with bags in the project build section - here's one example.
Click here.