Jeep rear discs on an 8 3/4 axle solution

Here is what I know so far. A new disk brake set up for an 8 3/4" axle will run me around $700, I still need to buy a set of new axles for around $200 when I cut the B body rear down to the A body length. Since Im going to cut the axle down anyway, why cant I just get the whole rear axle from the jeep ($150)and cut the ends off and graft them to the 8 3/4"? This solves the fitment issue of the brakes on the 8 3/4 axle. Then I can have the jeep axles cut and resplined for the 8 3/4 center chunk. Or have a custom set of axles w/ 5x4.5 made to fit the set up.
Thoughts?
Andrew