Just put a rebuilt slim ATE booster and large bore master cylinder up on Ebay. Here are the links.
Booster
http://cgi.ebay.com/ebaymotors/BMW-...r_Truck_Parts_Accessories&hash=item3a5b57cf79
Master cylinder
http://cgi.ebay.com/ebaymotors/BMW-...r_Truck_Parts_Accessories&hash=item3a5b57ebb3
Booster
http://cgi.ebay.com/ebaymotors/BMW-...r_Truck_Parts_Accessories&hash=item3a5b57cf79
Master cylinder
http://cgi.ebay.com/ebaymotors/BMW-...r_Truck_Parts_Accessories&hash=item3a5b57ebb3