skiWVUxtm

Just checking if I'm on the right track for my setup:

From the battery positive terminal I'm running 4 awg wire, with an inline fuse within 18" of the battery, to a fused distribution block in the truck (more like the middle of the vehicle). From the distribution block I'll be running two 8 awg wires, one to my eD NINe.4 amplifier and the other to my PSU though initially I'll only be setting up the amplifier (will add the PC setup later). The amplifier will be powering two front speakers (Infinity Kappa 680.7cs) and a sub (Infinity Reference 850w). I'll be using 12 awg wire to connect both the speakers and sub. Since I won't be setting up the PSU/PC quite yet I'll just hook up the amplifier to my stock headunit for the time being. That should be it for my audio setup...

Couple questions:
1. Do I need to run 4 awg wire from the battery negative terminal to the vehicle's body (along with the grounds from the amplifier and PSU)?
2. Should the ground wire from the amplifier and PSU both be attached to the same grounding point on the vehicle's body or does it really matter? The reason I ask is because the PSU/PC setup will most likely be in my center console (in place of my CD changer).
3. Is it fine to connect both the speakers and sub using the 12 awg wire?

Any other feedback/suggestions would be greatly appreciated =)

Thanks!

- TL