Like stated start with big 3 upgrade then upgrade the stock battery to a xs d3400. I ran more than you have off of just that and I never dropped under 12.8 volts.

 

I will echo the above post. Upgrading your wiring and battery will do more for "dimming lights" than an alternator upgrade. Since you run the system while the truck is off, you may consider adding a second battery in parallel.

 

Why dont you run a capacitor?

 

Because they're the biggest con and waste of money possible in car audio? lol

 

A real cap bank (maxwell supercaps) are great but only if to have an alt to keep them powered up. The caps like your talking about (rockford fosgate, audiobahm) stuff like that actually stresses your electrical more than if you didn't have it

 

Use an Ohio generator. One I have on my 2011 is a250 amp unit I've had over 12 years on 5 different trucks with banging systems from day 1 and its never missed a beat. That alternator with dual red tops and all wiring beefed up stopped alt failures and dimming lights and put it on when I worked at soundwaves a local car audio shop here when inwas in college.