For the front you need the adapter bearings from Old Speed to slide the early 944 hub on the stock '66 front spindle. The caliper mounts are also custom from Old Speed. Then you need the modified grease caps from Old Speed. That is about it that is custom. The rest is Porsche parts all the way. Oh and the front rubber brake lines are disc front from a Beetle/Ghia. Easy once you have the parts.
The rear is tougher since you have a Swing-axle. Basically get the early 944 rear brakes complete and then send the hubs to Old Speed to machine them down to fit right, also the caliper mounting plate need drilled to support the larger swing outer bearing. About $100 for the rear mods. The rest is all Porsche parts.
Fairly straight forward but the parts start to add up $$$ after a while
Also see my rambling post on the horror of costs that I have encured over the span of this GL project.
Good Luck,