I looked into this on my 2011 F450. I could not find the parts I needed for the rear, finally decided to just buy a used complete axles I found on craigslist, but before I picked it up, I bought a new truck, 2018 F450 with the 15.5" brakes , problem solved.
I really think buying a complete axle would be the easiest, so many different parts that might need to be changed- brackets, calipers, rotors, flex brake lines, parking brake cables, brackets, shoes, the list COULD be long. I do not know which of these items are the same or different, it could be a real pain finding out.
Good luck nd let us know how it turns out!