There is always the XJ/MJ rear D44, but good luck finding one. A Ford 8.8" from one of their late model small sized trucks is a good choice too.
Some interesting swaps are to use a Scout II or SJ Jeep D44 with some aluminum spacers/adapters to make it match the front D30 in lug pattern. They are only 2" inches narrower, but the SJ has six lugs and the Scout uses the bigger 5x5.5" pattern as opposed to the YJs 5x4.5" pattern. Alot of Ford, AMC, and Chrysler cars used the same lug pattern as the YJ too. Some good axles came under some of those cars.