If you are going to be pulling heavy amperage, might I suggest, if you have room, add a second battery. We did this to our Heavy Rescue truck because we have alot of emergency lights (full light bar, rear strobes, side strobes, headlight wig wags, arrow stick, alternators on the corners of the roof, and oscillators in the grille and three siren heads on it. That's alot of stuff....but you can see us comming down the road!!!
) Just run them in series Battery 1 negative to ground, positive to battery 2's negative, positive to the vehicle electrical system. This will act like one HUGE battery.