Came in a bit late but have you considered getting a 2500watt Hybrid invertor? Works on both solar, battery and electricity. Will only kick in when the power cuts. Added to this you are not limited to a battery bank. The more batteries you add the longer you can use it. Do not need solar since batteries can charge via electricity.
There are several nice ones on the market. Would recommend staying away from Phoenix systems. The are in parts, e.g. charging unit, inverter unit, power unit, etc. They tend to work out much more than a complete hybrid system. Your biggest outlay on a hybrid would be your battery bank. Try to stay away from Gel, but they are not bad if you add a table shaker to the system. Get 24V input as a minimum. 12v units suck a battery dry in minutes.
Apart from that I cannot give more advise. In my country power outages is part of daily life and have been using a hybrid system for the past 5 years without fail. Even run my house light off it. They just do not like geysers, kettles, ovens and microwaves. It handles it but drains the batteries in minutes.