Axles-Gears-Powr-Lok setup

Your list covers the "go", but you forgot about the "whoa".
Your A body brake setup won't work with the large bolt pattern axles, even if you redrill the drums.
Easiest would be large bolt drums (and backing plates/hardware), then you won't have to mess around with different masters and proportioning valves- so as long as you've got an order going to Dr. Diff, you may as well add this to the list:
Mopar Drum Brake Assembly