Rob, I don't know what the situation in California is, but here in Ontario, the certified techs are all ganged up against R12A, even though kits are legally sold in all auto parts stores and Walmart. The kits even include adaptors to change old R12 fittings to the required R134A type. I can see why "the establishment" is against DIYers doing their own conversions for a tiny fraction of the R134A price. I have read, though, that R12A conversions are not legal in the U.S., so kits may be harder to find, but they're plentiful on eBay.