My Duster had power front disc brakes from the factory with a 7-1/4" rear end. I built an large bolt pattern 8-1/4 rear (3.55:1 & Dana Trac Lok limited slip) which came out of my 1973 Dart Sport 340 and used 1995 Jeep Cherokee rear disc brakes on it. It was cheap (got my complete set-up for ~$200.00 shipped including new pads & rotors), easy to find parts for, and kept everything "Mopar".
I bought a new aluminum master cylinder kit (1-1/8" bore aluminum master cylinder & aluminum 4 bolt - 2 bolt adapter) from the Mopar Action guy (R. Ehrenberg) off eBay for $90.00 shipped.
I also used the correct Jeep brake hoses which cost me $45.00 out the door at the local Advance Auto Parts.
Everything works awesome together, I absolutely love the combination!
I tried locking it up on slick/wet roads and the car stays nice and straight.