I could use an existing wire (coming from the shore power charger) that's 8 gauge by the looks of it. It might be 6, I figure it's at least 8.
8 gauge will handle 68 amps. I think I'll use that. The Fourwinds site says " Voltage Regulator: 12V or 24V to 60 Amps" so I guess I'l plan to go with that.
I'm using this site Blue Sea Systems