Also try kelderman.com
They have a number of suspensions suited for 1 ton and a little larger "pickup trucks" which would be sized about right for our old 2 tons. I had been eyeballing one of their systems a few years ago that had 4 links borrowed from semi trailer suspension which are cheap and easy to replace and very robust, and a 5th link over the axle, and 2 smaller air bags per side.

For the front axle I'm not sure how you can really do full air ride and how it wold be worthwhile, there is just not much room at all. look how close the axle and springs are to the frame now, if you want it "slammed" then you don't have much room to play with.
Here's how I added air helpers on the front of mine
https://picasaweb.google.com/lh/photo/XhpxTSOlop6_8t-sRPk_rNMTjNZETYmyPJy0liipFm0?feat=directlink
can't seem to find a picture of it instaled, but I have an extra 2" of room to work with from stock because of the axle (2" drop) and custom springs to make up that 2" and get it back to stock height.

Here are my rear air helper springs
https://picasaweb.google.com/lh/photo/XTzkG6xsrAUBw5N5PhhG8tMTjNZETYmyPJy0liipFm0?feat=directlink

•1951 GMC 250 in the Project Journals
•1948 Chevrolet 6400 - Detroit Diesel 4-53T - Roadranger 10 speed overdrive - 4 wheel disc brakes
•1952 Chevrolet 3800 pickup
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"First, get a clear notion of what you desire to accomplish, and then in all probability you will succeed in doing it..." -Henry Maudslay-