Sounds like a really nice combo you got there. What was your question? Specs on the equipment or info. on how to install it all? You say your car is stock, the next step I would take is looking into an aftermarket head unit to properly process and tune your music. You'll lose alot of sound quality and flexibilty trying to run through a stock head unit.

And a capacitor is an electrical component that is installed between your battery and amp, short bursts of power are stored and theoretcially helps reduce voltage drops to your amplifier, which in turn keeps your amp playing at full potential. Although the effectiveness is controversial, it couldn't hurt.