Danhami, where in California are you? I'm in Sonoma County Nor. Cal. and there is a brake parts supplier here who can still get asbestos friction. Converting from "organic" to asbestos is like adding a power booster without the drum/rotor eating effects of metalic friction.
I have also found asbestos pads for GM "metric" calipers on ebay. So the "metric" calipers are an option to consider. There is even a rear brake version of those that has an e-brake.
