Actually, depending on your year model SC you only need to change to 94-up 'Stang hubs on the front and either re-drill and re-stud the the rear hubs or get some 99 Cobra rear hubs. The rotors (front 91-up, rear all years) can also be redrilled.
While you can change/update calipers and rotors on the 93-up SC, it is not required just to get the 4.5" bolt pattern.
It is a fair amount of work, but not necessarily expensive.