The handbrake shoe setup on the 100 series is different to the later models and the diameter of the centre hat of the rotor is different I think, it's certainly shaped differently at the very least.
Fitting a 200 series rear end isn't too difficult by the look of it, and allows a 200 series rear swaybar to fit.
Some people with 2/7/9 series have machined the disc section off the rotors, leaving just the hat section to retain handbrake operation, and fitted an S60R vented rotor over the top with longer wheel studs, and used S60R or Cayenne calipers.
Given that the rear brakes typically only do about 30% of the braking work, I personally prefer to put the time, money and mental capacity into making things go faster.