Those neato power panels to mount Redarc etc, how u do dat?

Looking to gather the disparate posts & links for how folks set up their dual battery electronics. Those boards along the inside of the bed with electronics mounted on them look very cool, but then you can't haul stuff or get them wet. So I'm thinking of mounting the electronics in the back of the cab but of course I have an access cab, so not very much room to work with. I really want to avoid drilling through metal if it can be avoided, very humid in WA state.

I suppose I could just run a single G31AGM battery since I'm only going to be running a fridge and rarely a winch, but hate to get stuck unable to start because the battery ran down. What made you decide to mount your house battery where you did and how much effort did it take? Or could I maybe mount the battery and electronics in the bed in front of the passenger wheel well and hide it behind some kind of cover (which then means it can't get wet)? I think I read that someone even mounted their spare on the back and put the house battery under the bed.

Sometimes with so many options available it's hard to even get started. /sigh