All great advice so far. Some other thoughts to consider:
1. Anything with a heating element is a power hog. Be sure 1000W of inverter is enough. Only means you have to limit those activities to generator time.
2. If adding an inverter, I'm sure you pick a good wire size. If replacing the converter with an inverter/charger/transfer switch, the wire size to the battery will probably need updating as well.
3. If only using lights, water pump, water heater, and fridge, two batteries will easily last 3-4 days without a charge. That all changes once coffee pots, tv's, toasters, and furnaces are added to the mix. A furnace used at comfortable temperatures will require an extended generator run to put some umph back in the batteries.
4. Often times, a generator will have more capacity than a converter charging the batteries use. Adding a stand alone charger will help speed the bulk charge cycle.