A good all round and value for money option is the EBC yellow pads. They are available for most Porsche applications they are an 800degree pad from memory, are easy on discs and work from almost dead cold. We are using these on our '96 VW multivan and have had them fitted since September '95 and they have worn very well, and the discs are showing no sign of wear!

I have also used the porterfields but have found them to be hard on discs, although that may have been attributable to the driver as he is very hard on brakes.