Replacing the struts and brake assembly with HP 2 ones is an option, of course. But the UFO brake is not as black as it is painted. With all hardware (brake booster, pressure accumulator, calipers, discs and pads) in well conditions this brake works reliably.
The brake discs are still available in Germany. http://trshop.audi.de/konakart/SelectProd.do?prodId=41810&manufacturer=manufacturer&category=Räder%2C+Bremsen&name=BREMSSCHEIBE&model=0001
The price is about 340 GBP each.
May be one can find some more suppliers in Germany.

Beste Grüße
Tim