You'll need 10 x 2 1/2 large bolt pattern: backing plates, drums, brake shoes, brake cylinders, brake hardware kit: http://www.doctordiff.com/mopar-10-x-2-1-2-drum-brake-assembly.html Or you can get all that stuff at rockauto or local parts store. Might be cheaper with shipping.
Then take the center section to a rebuilder. Have you tried Sutton Engineering?