So the reasoning behind what I did this holiday was that I hated having tons of wires running in and out of my dash and firewall for switches and power and hated having them run all the way from the battery. So I decided, install another fuse block.
The fuse block is a Buss from Autozone, about 8 bucks I think. Has 6 30A outputs and a 150A input.
The wire I used was some 4ga stranded which is rated for 70A. I wanted to have something rated for 150A, but that was 1/0ga, and that's just too thick and inflexible for auto applications.
Installed a marine rated Buss circuit breaker rated for 100A in line between power and fuse block.
I tapped power from the front of the battery junction box. It looked it had a 4 or 2ga wire supplying power so I figured I was fine.
Where I mounted the breaker, it was PERFECT. It was just in front of the trailer relay block, and already had one hole, and just drilled another, and it was a beautiful fit.
The fuse block got put behind the under dash cover panel (the one you remove to get the real fuse block), and bolted onto the metal member about where your shins would be, right in the center of it. I'll get pictures of that later today.
Here's the batt junction box and breaker.
The electrical tape over the batt junc box was because the air box I made had been touching that hot post and arcing. So I taped over that spot on the air box and then on the post.