83 camaro, wire size, battery to amp

I always like to get a reference from those with more experience than myself…

I have an old school 83 Camaro with a 160 alternator, two deep cycle batteries, I plan on running 4 shallow mount 10” SVC Clarions on a Hifonics Class D 2000 watt. I also have 2 4 channel SPL’s amps for Hi’s… Ok now my question other than Big Three what would you recommend in gauge size (0/1 or 2)from the battery to inside the vehicle. And would it be better to run 2 gauge wires from the alternator one to each battery. I also have a couple of Battery Caps, and Cap Cell just incase

So 4 gauge from the D Block to the surrounding amps, even the largest?