A Body Disc Brake Swap 101

I am looking at the straight up swap for disc brakes front conversion for my wife's 68 four door dart. I see both the mancini and doctor diff kits. No chance of finding a donor car for this on the big island of Hawaii! Disc conversion is a priority for safety. I want it soup to nuts, don't want to get into and have anything missing. What's the recommend on this? The valiant in my avatar, I just took the whole front end off a disc brake duster. No chance of that where I live now!