So, as the parts came in, they sat around for a while(ok, a good while) finally got around to installing my dual setup.
I picked up the Keyline Isolator 300amp(for future, friends trying to talk me into Overlanding.. haha) and AGM H6(Costco). The design for the battery terminal on the back of the isolator could use some redesign, or make it like their 140amp isolators. If you buy their kit, you get the right terminals to fit from the looks of it. I bought some copper tubing and made my own lugs to fit correctly on the back terminals..
I used some red wire-loom for positive cables, but, I might switch it out with black. I picked up MTA 0300839 fuse block to use on it. I did pick up a 4 Relay/12 Fuse holder, just need to figure where to mount it, most likely in the corner next to the aux battery on that corner bracket. I'm going to re-wire it using the more flexible silicon wires.
I did go the sensor route with the negative cable(used 2AWG). My old man gave me 1AWG red/black welding cable, so used the 1AWG for the positive. I connected some leads to the aux battery so I'm able to plug it into a maintainer, comes out by the bottom front grill.
I left some of slack on the main cables if I need to move/route them. I used 2 fuse, between the isolator and main/aux battery. I ordered some wire loom mounting clips to clean up that side wiring/cabling. Most likely move the fuse onto the firewall for a cleaner look.
Don't mind that cable hanging down, it's going to get re-routed, it's for the LED strips.