Ranger rear brakes, best to worst:
'10-11 Ranger disc - largest diameter, thickest, vented. Only knock is the parking brake integral to the rotor.
'94+ Mustang Cobra - large, thick, vented
Explorer discs - large, but solid Note: There is a small Explorer disc (goes with the smaller front discs)
10" Ranger with Aerostar finned drums
10" Ranger
'94+ V-6 Mustang discs - small, solid
9" Ranger
Although between the last 2, it is a toss up. Rangers are better in single stop; Mustangs are better on track.
In all cases, you need OEM brake block or brake adjuster if you are changing.
I have done semi scientific testing with all. Results are measuring stopping distance using same force on brake pedal/adjusting bias so that the rears don't lock 1st when empty (anti lock fuse pulled). <Rear brakes locking 1st on ice is bad thing, and Calgary seems to be good at icy winter roads>.
Haven't played with aftermarket - most were focused on Mustang fronts and larger diameter than would fit my rims. Again, for Calgary roads, I need a little rubber between road and rim - when I was concentrating more on looking for potholes, man hole covers, etc than on enjoying the drive in my Focus SVT, I came back to a Ranger.