You can order the MasterPlate and SuperBar directly from MasterGage or one of the following distributors:
www.mcfeelys.com
www.woodworkingshop.com
800-279-4441
http://forrest.woodmall.com/accessories.html
www.amazon,com/toolcrib
www.grizzly.com
www.7corners.com
www.japanwoodworker.com