A friend of mine had to completely re-do his front brakes when Stainless Steel Brakes closed up a few years ago. SSBC is back, but rotors for their kits were unavailable for a few years.
I needed to replace the front brakes on my SSBC kit (A153 I think) a couple seasons ago, the pads and rotors were from a 67 Mustang GT, I was able to buy them at the local auto parts store.