Then the Optimas are really an automotive battery. You probably wouldn't be discharging them and they'd be fine with being more agressively charged if they were AGM's.

The Optimas (which are intended as engine start batteries) are really pretty durable.

DC Battery Specialists (out of Miami) had the best prices. http://www.dcbattery.com/optima_red.html

The Optimas are really "small" footprints and can be located outside of the engine room without too much work. I'd not have them in a space that is completely sealed (any battery can, in extreme situations, out gas).