http://www.renntech.org/forums/index.php?showtopic=2810
We do not replace the wear sensors unless the light is on. We reuse them. Or, if you are like me, they have been removed from the pads.
For the pads Porsche uses Textar in the rear. Textar is owned by another company and that comany has bought up several other friction material companies. Galfer is used on the rear. So brand X and brand Y pads may be owned by the same company and marketed under different names. For a street car I look at the friction ratings. The oem front and rear are rated FF. We have put in FE and I just bought a set of Mintex that are EE. We put in a set of Hawk rated at GG but they make some noise. If you are going to keep the wear sensors then make sure non oem pads have the holes.
You can turn the rotors but the specs are just 2 mm so there is not much there to remain in spec. On a street car with street pads you should go through 2-3 sets of pads before it is time to replace the rotors. We measure the rotors to see if they are within specs.
Most of our local owners use Ate. But at our work on cars days people show up with different brands and I put them in as long as it is Dot 4. They are all still alive....