Im tryn to figure out what amp alt to get and how many batteries i need? Im running 4500 watts. I was thinking 220 amp and two battiers.I need brands also
Your charging system will depend strictly on how efficient the amps is.
I would go with a the biggest alt for your car (why not? might want to upgrade again later) and also another battery in the back. Isolator is not required at all unless you want to separate the two batteries.