Assuming the boat was configured by the factory for the generator option, then just wire the generator per the factory schematic.
A charger/inverter requires an additional transfer switch, so the typical solution is to use a charger, wired in at the factory locations, to replace the missing part.
An inverter is handy, so on my boat I added additional receptacles powered by the inverter. I also connected my TV, Blu-Ray player, TV antenna amplifier, Cable TV box and IR repeater by the inverter. All this so I don't have to kick on the gen while at hook to watch TV. The inverter receptacles are handy for charging phones and laptop computers w/o turning on the gen.
