I need to know what wire gauge I should go with for my subs, component and coaxial speakers, power to junction block, power from junction to amps.
I also would like to know what you all would recommend for the capacitor.
Also if yall could look over my rough wiring diagram and make sure I have it right.

The only thing real special about it is I have dual 4ohm coil subs that I wired the coils in parallel, than wired the subs together in series which produces 4ohm’s resistance. Then bridge the amp with the two subs.

If you notice, I have a set of dashed lines going off the page for sub audio input, amp on/of wire, and power, that is for a 12-15” 700watt (ish) sub that I want to add on later.

Here is the list of bits and some info on them
Sony CDX-GT400 head unit
Sony CDX-T67 cd changer
Infinity reference series 6010CS components 90W RMS 270W peak
Infinity reference series 6012i coaxial 60W RMS 180W peak
Kicker ZX200.4 amp Certified peak power 250W (for all 4 infinities)
Kicker CVR8 subs 200W RMS 400W peak
Xtreme XA-3002 amp 300W peak

 

With power cable, bigger is always better. =)

I don't know enough about those particular amps in order to say what would be required. I do know that I noticed a significant difference in my own setup when switching from 8 gauge to 4 gauge. I think I would always use at least 4 gauge for a subwoofer amp. The amplifier for your components would probably be perfectly happy with 8 gauge.