Many thanks for the advise on the AGMs.
I plan on using 2 8D flooded (wet) for cranking the Yanmar 480s and 2 8D AGM batteries for the House/Electronics. I plan to have the House/Electronics bank batteries wired together in parallel with one of the Yanmar alternators providing charge while underway and its own dedicated battery charger set to "AGM".
I plan to keep the 2 8D cranking batteries separate from each other except for charging, when I plan to use a voltage sensitive relay battery combiner. I plan to have the other Yanmar alternator provide charge while underway and supply the cranking bank with its own dedicated battery charger set to "Flooded".
What are your thoughts and ideas about this preliminary plan? I currently have a stand alone battery to crank a 3 cylinder Yanmar powered Kohler 8-32EOZD generator. How do you think I should incorporate it into the system? I need to provide a charge to the battery when it is not in use? The current battery used by the generator is a standard marine sealed cranking battery.