95 Cherokee rear discs (pics)

exactly. rear brakes. rotors, lines, bads shouldn't be a problem. But spash shield, mounting bracket, calipers will be.
How does the emergency brake work? Mechanical?

What else is needed for an 8 3/4 axle (bbp)?

the splash shield and caliper bracket all comes off in one piece. Just source your parts from a 95-99 Gran Cherokee and all will be fine. Parking brake is mechanical. Blue Missile has the parking brake layed out, I'm still jacking with mine. My diff is a 8.25 not a 8.75. Blue Missile has a thread on doing the Cherokee swap to the 8.75.