As far as what I know (and that might be wrong) the manual transfer case will work fine behind the auto EXCEPT you will have to make a filler for the trans tunnel for the other shifter.
The column will need exchange for the auto shift lever, the cooler lines up to the rad, the arm from the bottom of the column to the trans, a rad that has the cooler in it (most replacements simply have them so check for the fittings being there already) and you might have to change the cluster (if you want the shift indicator) Ironically my manual has an auto cluster (and column) in it.
to do the high to low range thing it will have to be in park, AND if you ever end up in nutural 4x4 the engine will have to be turned off to get the trans back into park, and the x-fer into a gear again.
once the trans is in park the engine can be restarted and normal shifting again.
All the wiring for the electrical x-fer case, IMO, is a waste of time and money, unless you want nothing on the trans tunnel.
Greg