Rear Disc Brake Conversion

I think I am going to do a disc brake swap on the rear. I have an 8 3/4 rear and was leaning towards Doctordiffs rear disc brake setup. I talked to him (Cass) on the phone today. Very knowledable. I think I am going to order them on Friday. (I bought the axles from him last month.) Anybody else use these brakes on their car? How about the Kit summit sells. I want to retain the parking brake. Let me know what yall think of these brakes.