I thought the 11's still had AJP clutch masters?
Its easy enough to check, it will either say AJP or Magura on the cap.
Also, you can mount up a Magura clutch master easily enough, which makes getting spares for it much easier.
Moose make aftermarket levers for the AJP master, I think they come through partsunlimited. I don't live in the states, so can't confirm, but I had read that one of the main aftermarket company does make cheap levers for gasgas'.