These are new, more affordable rear disc brake kits from Baer, and include the parking brake mechanism. Not too badly priced.
http://www.baer.com/products/complete/ironsport.php

Couldn't get the brake website to come up, but your car looks really good. Only way to build one is from scratch!

Thanks, this one is from scratch. Not much of a choice for me, as it was full of rust. LINK: That's weird, the link worked for me.

I saw an articlein Mustang Monthly this past month about Mustang Baer Brakes. The fronts are 12" Serious Street Baer Claws and11.35" Serious Street rear drum to disc conversions that use the stock parking brake cable. Sounds pretty stout!