theres a post on tampa racing of a guy selling PBR dual piston calipers (not cobra) for 50 bucks if your interested in them..
http://www.tamparacing.com/forums/ford-tech-sale/613661-pbr-calipers-dual-piston-50-a.html
http://www.tamparacing.com/forums/ford-tech-sale/613661-pbr-calipers-dual-piston-50-a.html