77 Cherokee.... lift options and more questions...

...... I see you know something about the 77 Cherokee... so I thought I'd ask a few questions if you do not mind.
I am a IH Scout guy.... and generally know everything about them.... but not too proud to say I know NOTHING about Jeeps!
I met the owner of a really nice 77 full size Cherokee today... and helped him with a thermostat problem. (he was fairly mechanically inept)  He then asked if I could help him build up his Cherokee (is it a "Chief"??).
It is a 2 door "fulltime 4x4" as he told me, 360 v8, auto.  It has sealed from hubs, so they must be fulltime or auto lockers.... and there is a "FULL - LOW RANGE" lever under the right hand dropped from the drivers seat.
It is spring over... and they springs seem fairly flat and "swimmy" on corners.  There is a 1" metal lift block between springs and axle tube.  Also the front end has VERY LONG shackles that are about 6" or so from bolt to bolt.
I do not know how much of this is stick or standard... but wanted to paint you the picture of what I was looking at.
A previous owner did a hack job on wiring... so that will be straight forward but a nightmare.
The questions I have are:
-what is this thing?
-what additives go in the diffs... limited slip or standard?
-what are the best lift spring set-ups?  I want to lift it about 4"-6", and not by stacking lift blocks.
I know from Scouts that "Rough Country" and "Tuff Country" are crap... so what do the Jeep guys really suggest?
Triangle? / Rancho? / Superlift?  Is there a part number you can suggest, and what are the price ranges?
I am assuming I get rid of the long shackles and go with stock?.... how long were the stack ones?
I think that is it for now... thanks and I look forward to your reply.
-Steve Bigler   (stevebigler@ca.rr.com)
*Oh also... behind the chrome grill there is clearly the set-up for a second set of headlights, but there are no buckets or anything -just the cutouts.  Is this standard too?