+1 on the Crown Vic. I'm looking at that myself right now for an 8" Comet rear on my Model A. From what I've read so far, 92-02 can be installed with very little fabricating. The curved bottom part of the flange needs to be cut off to match the top; and a small spacer is fabricated to shim the bearing support.
The alternative to that is an adapter bracket on Ebay for $150, that then uses 94-04 Mustang rear discs, calipers, etc. It also needs an adapter to go between two different brake line configurations.