What's your budget?
If you're looking for super cheap, junkyard swaps you're out of luck. You can't just bolt Mustang knuckles on any Ranger. They're entirely different front suspensions. Mustang = MacPherson strut, 98+ Ranger = Double A arms.
If you just want relatively cheap access to Mustang brakes, there have been custom kits in the past that used adapters that bolted Mustang calipers onto Ranger knuckles. Then, they took Ranger brake rotors and turned them down on a lathe until they were just a hub for the Mustang rotors. You can search here and other Ranger forums for "Cobra brakes" to see pics and get ideas. The kits haven't been made in several years, but you could do the same thing. This basic process would be the same for any year Ranger, but the custom caliper adapter would change depending on the year of the truck and the knuckle used. If you have access to a lathe, this could be done for a couple hundred bucks (plus the cost of the Mustang parts). If you have it made by somebody else, it would probably cost a few hundred bucks (plus the cost of the Mustang parts). I think the last batch of hub/adapter kits were almost $500, and that was at least 5 years ago. I might have a spare kit on the shelf...
If you were starting with an I beam truck, AJE makes a bolt in Mustang front suspension/k member setup. It's not a low budget proposition, but reduces front end weight by a couple of hundred pounds and allows any Fox/SN95 Mustang suspension and brake components to simply bolt on. And it also makes Mustang engine swaps a bit easier.