I tried all over to find an alternative but gave up in the end. What I did find out though is that Brembo cast or stamp the safe minimum disc thickness into the disc either on the boss or onto the circumference outer edge. I believe it is 30mm for the front and 22mm for the rear on a QPV. What this meant on my car was I was able to get all four skimmed on the car and just replace the pads. The guy who skimmed them said that there was enough metal for another skim.
When I did mine 2 years ago costs for all four wheels were
New Maserati discs and pads £1850 + fitting.
EBC pads + skimming the discs and fitting the pads £380
I know this won't be for everyone but these guys seem to think it okay -
http://www.thesupercarrooms.co.uk/maserati-brake-disc-skimming-repair