Any of the 10 bolt half ton pickup rear axles. For a brake upgrade, you could go with a 2wd half ton Suburban rear axle, and get JB 6 brakes instead of JB 5 you probably have. You'd have to swap master cylinder too though to get best operation of it, and the calipers and rotors may be different?
Simpler to stay with the pickup axle.
Others are welcome to add comments to the discussion...