If you are mostly day sailing, and plugging in a charger while at the dock, a pseudo-Marine deep cycle will work ok. I use two Nautalus group 27’s (sold at Menards) on my O’Day 322. Not sure who makes them, but they work ok for me. Under $100 a piece (maybe $75 when on sale). I have had mine for a couple of years. Runs fridge, cabin lights, anchor light when on the hook.
For more intense amp-hour needs, 6-volt golf cart batteries seem to be a good value.
Greg