battery optima diehard

I have 2 Rockford 1500.1 BDCP'S at 1 ohm, 1 arc audio 300.4. I have the big 3, stock 120 amp alt, and new Die hard advance gold AGM 875 cca under the hood. I have some generic batt that is supposed to be equal to somewhere in between xs power D3400-D3100. The car audio shop swears by this batt...

For my 2 12" L7 ported, im gonna have them on a zx1000.1 (probably more likely) or a zx1500.1. I have an 1800 watt amp wirin kit (pretty sure its 4awg), and Im gonna do the big 3 with 0 awg. In my 2007 pontiac g6 v6 sedan, with stock alt (120 amps is what it said online about it, so i wont...