Also the Duracell group 31 AGM at Sam's Club are made by Deka and have the exact same specs as the Deka (East Penn) 8A31DT
. They are the same as the Deka Intimidator AGM marine/rv battery. A lot less expensive to get the Duracell stickered ones for $180 at Sam's than the Deka stickered ones for over $300. They were $20 off at Sam's earlier this week, but that sale ended on the 24th.
Another less expensive option if access for watering the batteries is the only problem, would be to add a "Flow-Rite" watering system to your existing wet cell batteries. Pretty simple to use. I have them on my center console boat as watering 5 of the 6 batteries on that is a huge pain. Basically you hook a squeeze bulb and water supply line to a fitting on an extension hose and pump the bulb to top off the batteries. It senses the level needed and you don't have to pull the caps at all.
They have a couple of configurations. Their Pro Fill version can be pricey, but they have less expensive models. I have the Qwik Fill version on my boat.