Go with the recommendation of your local electrician. The 5 amp switch I mentioned is basically a 6 amp breaker as when the current exceeds 6 amps it trips and shut off the current. The breaker of course will be at the input of the inverter. Your inverter outputs constant 5 amps, it the input connected to local electric grid that sometimes fluctuates up and down considerably and needs protection.
A transformer will indeed help generate extra wattage but still 2000 W!! Anyway, if it is working for your brother it will work for you too.
Just make sure you have a electrician setup the inverter properly as you do not have a central circuit breaker. The negative of the inverter input and negative of the inverter output should be connected together. There should not be any device in between them. The negatives of all the rooms appliances need to be connected to each other too. An electrician will tell you what I am saying better. My own wiring was done by a electrician who charged Rs. 500 for the work. It is better to get it done professionally or lose your inverter to a power spike.