Square wave or Sign wave or modified sign wave inverter 2 kva -which is better ?

Hi,

Friends, I need a new home inverter with atleast 2 KVA capacity. I can even go for higher capacity but should work on maximum 2 batteries. Now problem is that I can't find a suitable UPS inverter .. I think UPS is built in all inverter now a days so should have UPS feature too.

What I found that most double battery inverters are less than 2KVA. I found a 2.2 KVA luminous inverter but its square wave. Now again more confusion as it is said that square wave inverter are not good. Please advice what should a buy - pure sign wave or square waves . Also advice you can find a good 2 KVA or more inverter which runs on 2 batteries ie. 24 volts.

Thanks for the support :)

EDIT:

And what the hell is modified sign wave inverter , are they any good because the one I found 2.2 KVA with 2 battery support is actually modified sign wave inverter .