It depends on what type of driving you do. If your doing rock crawling and lots of off road stuff, I would get the manuals. If you are using it for a grocery getter/paved road mostly then get the automatics.
Automatics do not use vacuum. They are similar to the 95-97 style but stronger built.
If your going to toss the old ones out, let me know and I'd like to have them (all the pieces).
White 96,4x4 w/Y2K motor,Warn man.hubs,K&N filter, 3row rad., twin 16" electric fans w/SPAL FAN-PWM, 1.4" body lift, 4" UPYOURKIA lift kit,265 75-16 TREADWRIGHT GUARD DOG TIRES ON 16" DC-2 wheels, 140 amp alt. dual batts.