If AC is a requirement, for all practical purposes, generator is the way to go. We have a Yamaha 2400watt and it handles the AC but is at the upper limit.
If you give up on AC and are otherwise modest in your power consumption, Solar/Battery Bank/Inverter is probably the better option. We have close to the system you describe on our boat and as long as we don't need AC it does just fine.
The suggestion to do an energy audit is probably the best option though. My idea of modest usage and yours may be completely different.
