You can do anything with the right tools, knowledge, or money to let someone else do it. Do you have one or all of those things?
The D44a is a POS, so scrap that idea. You'd be much better off with a Ford 8.8 or something along those lines.
Personally I see a lot of effort for little gains. I'd much rather leave the driveline as it is other than the axles and put the effort needed for the ZJ suspension into a custom double-trianglulated four link in the back and spring over on leaf springs in the front.
BTW, ZJ's ride on coils, not coil-overs. Big difference in tunability, expense, and ride quality.