I have been working on the Porsche 914 rear disc brakes. PMB Performance provided the kit to rebuild my calibers and the kit is nearly complete. You do however need some hard parts from your old calipers to finish the job. The kit includes a ready to rebuild caliper as well. For under $200 bucks shipped it is far better than spending nearly $400 per side buying a completed caliper that is not going to be any better than what you will get from this kit and your old calipers. I have a video coming of the rebuild and a quick picture of the second caliper after the parts were cleaned and laid out for final rebuilding. I have both completed but not yet installed. Video will come later. Brakes are important and wanted to show the process. Don't be afraid of brakes but you do need to know what your doing. This is the price you pay for converting or hot rodding old cars. Most of the time brakes will need to be at minimum rebuilt. At worst they need to be totally replaced. Don't' skimp on brakes, you need them.
PMB Performance is an excellent place for early Porsche brakes. pmbperformance.com