You need an alt able to feed the car requirements at iddle ( which usually stock alts are far away from that even at max output ). That's the more healtly output you can get for the charger system. And feed all acc relays from alt side of the ammeter line.

No need for amm bypass but just a good mantenience on cluster/amm isolators and clean and tight studs to the amm inner plate. Then extra wiring to save the bulkhead terminal weakness with a parallel path through the firewall and you will be set and safe