There's all kinds of nice distribution panels out there to buy, but you don't have to. You made me decide to simply rebuild and upgrade the original one on my boat. I really don't want to reconfigure the original boat to fit one of the new panels.
What do you mean the state of charge? Is that the digital 13.1V I'm looking at or the bar to the right? It doesn't seem like state of charge will be too accurate if it's simply a voltage read, unless the batteries have rested long enough.
I just checked my batteries after the boat has sat for a week. I could tell the age of each battery by the voltage from past experience.