Since you are in Florida, R12. Do not settle for r134a. I'm moving back to R12 when I replace my condenser on my 300TE soon. If where you live gets no higher than 90F, r134a is fine...anything higher and its no longer satisfactory unless you have a thing for sweat. If your "mechanic" says you can't use it anymore, find a new one. You can get it off craigslist with a $20 license or "intent to resell". You will be REQUIRED to flush the ENTIRE system if you had r134a in there previously. Its worth the extra effort though, trust me.
Maybe the newer models use Bosch, ours do not. Ignore them.