www.sport-conrad.de
www.backcountry.com
The ones above are p12 racing w/wide brakes, and the ones you'll find on backcountry.com are FKS185 (if you can find them, they could be sold out). Also check tramdock, untracked, and ebay. And the TGR boards. You'll definitely be able to find them somewhere, its just a matter of how much you want to pay. Also if you are only fitting them to skis around 100mm waist, bending the regular brakes is easier than trying to find (and afford) new ones. There are tutorials on how to bend on TGR and perhaps here. But TGR for sure has them. Do a search.