Thanks for all the feedback provided here.
I spent yesterday morning with some of those plastic battery boxes looking at different configurations. I'm still looking!
The choices of available space on the port side just aren't really optimal. The problem, I've determined, is the best space to efficiently house the batteries is where all the wiring comes together and is the backside of the lighting and bilge pump toggle switches. Unless I decide to relocate,(or encase), all my elect. terminations, this may turn out to be a "no go" after all.