Contemplating building up my electrical system before I get my big ole' DC I'm dreamin' of. Doing a separate charging system, with a 250-270 amp Mechman unit replacing my A/C compressor and my stock charging system undisturbed. I will currently be powering the amps in my sig (08zx750.1 and 08zx350.4), so roughly 1300 wats total. What AH battery would you guys use in the back for the time being? I do play my music for extended amounts of time with the car off btw.