rear axle/bags/brakes installation

[jhcolli]

I got a '69 GMC 1500 that originally had a 6-cylinder, 3-spd, 10-bolt rear with 6 lug all the way around. I want to replace the rear axle with a 12 bolt, Dana 60, or 9". I'll probably install a big-block later on because the 350 in the truck is tired. I want to install air bags for a nice and adjustable ride, and I would also like rear disc brakes. If anybody knows a fabricator that makes what I am looking to install, please let me know. If I can only get the rear axle, minus the brakes, who makes brakes that I can buy or interchange for the rear?

Thanks