Not hijacking this treat or anything, but at topic at hand its actually not that hard if you take your time to do the research and not just here at CC, but also at Naxja etc etc.
And I'm saying this because I think I'm on the same boat as you are my friend, mine its also a 4.0 2wd trying to convert it to a 4wd very close to Pete's specs actually. And not an accomplished mechanic or anything but this truck are so straight forward (not counting electronics; those are a PITA) that after all month of research I decided to pull the trigger on parts.
Ax15 94+ come with the external slave (you want that trust me)
And the transmission thing that volts into it (forgot the name) you need that aswell.
Come on man! Lets do it