I've been dealing with this cab airbag issue for a while now and doing research on the right parts talking to Firestone, PowerPacker, and Ohio Hydraulics. I've noticed as well that prices have doubled, so figured I'd share what I've learned to make it easier for other since I appreciate getting info of this forum as well.
Here is the PowerPacker drawing for the airshock assy that fits my LMTV (PP958900UP). The drawing shows the parts and part numbers for the assembly.
There are some discussions for a KA5066. This is a service kit containing the parts as shown on the drawing. The engineer I spoke to at PowerPacker originally suggested the KA5066. However, after research and more conversation, I discovered that the PP958900 is the correct part. In speaking with PowerPacker on 19JA22 they confirmed that they have all of the above in stock at this time.
I've asked them if the KA5066 is interchangeable with the PP958900 are interchangeable. All I've gotten from them is that they are different bags and shocks, but no answer if they are interchangeable. From what I have seen on the post and other places, it looks like the KA5066 will fit. From what I can tell so far, the PP958900 uses Firestone bags and the KA5066 uses Goodyear bags. I don't know what's fundamentally different other than that. If anyone else knows and wants to add in - please do. Due to the price difference, I will be ordering a set of the KA5066 and see how they work.
Hope this helps