The rear discs were available on Grand Cherokees, Liberties, Dakotas and Durangos. Not on regular Cherokees, although they are a popular swap. The Dak/Durango setup is usable, but need to use the Jeep 5x4.5 lug rotors.
Edit: Sometime around '98-'00? Grand Cherokees went to a larger (5x5?) bolt circle, so the same caveat applies to them as to the 6 lug Daks & Durangos. Use the earlier Jeep GC rotors.
Liberties had some revisions on pads & rotors, but as far as I know all remained 5x4.5 BC.