There are a lot of producers of batteries, but no matter which manufacturer you choose, please note that you must use batteries that can be discharged by 75-80% on a regular basis.
These batteries come in the following two groups:

Dry batteries:
AGM or Gel batteries:
Advantages: Maintenance free and near to none gas when charging.
Disadvantage: Less charging cycles than by wet batteries.

Wet Batteries:
Semitraction (flat plate) or tubular.
Advantages: Lower purchase cost and more charging cycles
Disadvantage: Maintenance must be done.

DO NOT use starting batteries.
They are not developed for deep discharge.

The size of the battery bank depends on the required cruising speed and motoring distance. Providing your local dealer with information on your boat and your motoring requirements, the optimal size of battery bank will be calculated.