that panel looks really small for 200amp, Also never seen dual breakers like that for a service disconnect..(of course not being an electrician and barely a hack at electrical there is plenty I havent seen) It might be that way to make it fit in the box.. as it appears to be fairly small and stuffed full. it definitely appears to be 100amp service to the box and they just have it on separate 100 and 80 amp circuits? 100 amp for the house and 80 for the AC. if you have to update and run wiring to the garage I'd think 3k-5k range for price. new box, new cafci breakers list prices.. not cheap. then of course you might need a new drop or underground wiring to your meter, and possibly new meter. electricians are not cheap either.. labor $$$$ This is the size and layout of a fairly modern 200amp service (2011) notice the size difference, the single breaker service disconnect etc. Most breakers are cafci(Combination Type Arc Fault Circuit Interrupters) -room outlets, light fixtures etc, except the 240v and certain other appliances(fridge is 20amp non-cafci) no real downsides to cafci although you can have issues with powerline networking interference tripping them. Consult a pro? California rules might be different on whats permissible.. that setup looks borderline hackjob to my amateur eyes.