Well I got this all sorted.
Using a National Luna Intelligent solenoid which automatically monitors/connects and disconnects the batteries or can be engaged with the controller in the cab.
The solenoid install instructions say to mount it upright but I found many people including outfitters/dealers install it flat with no issues, couldn't see why a solenoid position would matter, and I wanted to keep the cables as short as possible and the unit accessible just in case it gets wacky on me.
I've been monitoring each battery with my DVOM and it is working perfectly.
I have my winch hooked to the side terminals, one cable going to the fuse box I mounted in the rear that from there provides power and ground for the fridge, water system, etc.
<a href="https://www.flickr.com/photos/131523454@N04/16613379432" title="SAM_0201 by Kyle Houghtaling, on Flickr"><img src="https://farm9.staticflickr.com/8571/16613379432_c8aa00901d_c.jpg" width="800" height="534" alt="SAM_0201"></a>
In other news I am heading to Moab in a few weeks so have been finishing up some odds and ends with the truck. Also just been out hiking about every weekend and playing with a new camera I got. Pictures will be getting a lot better here. I'm no photographer but have been quite pleased with what I've been getting so far.
<a href="https://www.flickr.com/photos/131523454@N04/16426991640" title="SAM_0123 by Kyle Houghtaling, on Flickr"><img src="https://farm9.staticflickr.com/8615/16426991640_6c29104546_c.jpg" width="800" height="534" alt="SAM_0123"></a>