I'll try to remember to snap a pic of my battery shelf.
For the battery management question I swapped out my battery switch for a Blue Seas Automatic Charging Relay (ACR). This is the kit I installed:
https://www.bluesea.com/products/7649/Mini_Add-A-Battery_Kit_-_65AThe beauty of this set up is I don't have to worry about battery management anymore. My house battery and starting battery are isolated from each other. Not only do I not have to worry about killing my starting battery, my electronics don't see a voltage spike or drop when I start my engine. In the off chance I run a battery down, I have the option of combining the batteries by simply switching the switch to the combine position.
For you question as to the type of batteries I'm running. I was running two dual purpose group 27s. My house battery just died so I replaced it with a dedicated deep cycle battery.