Unless you have a high output alternator, dual batteries is hard on your electrical system. Now it's having to charge both batteries, that's why farad caps are bad, so a better alternator is good to get, unless you can figure out how to install dual-alternators, too, which would be cool. I think I have something in one of my Lowrider maagazines about that. I've seen a Honda Civic with 4 alternators and 16 10" or 12" subs in it on TV, so I'm sure 2 batteries and alternators should be no problem. Probably easy enough to get an alternator bracket, longer belt and a one-wire alternator. Sounds about like the easiest and best way to go.