Need Some Advice on my Setup

[nauc 10+ year member]

first, learn to set your amp gain right. heres how. the test tones are at the very bottom

Amplifier Level Setting Guide

Note:The following article describes the Amplifier Level Setting process for most car audio amplifiers, regardless of brand. Specific target voltages for applicable JL Audio amplifiers are included...

jlaudio.zendesk.com

if you dont get that right, everything else dont matter

 

[mastershake575 10+ year member]

Also my budget for everything subs a new amp and battery is 1000-1300 probably

You have a small alternator with an aggressive regulator. Ditch the aftermarket battery and use that money towards a performance alternator.

You might even be able to keep your amp, it's going to get alot louder just by switching alternators (I wouldn't be surprised if your actually creating less than 500 watts right now with your stock alternator).

Your amp (Polk D1000.1) has a 120amp fuse and is rated for 1200RMS, with good electrical it should get very loud with 2x12s