I have designed solar Inverters for Indian and Taiwanese.
I think you will be concerned with independent inverters (not Grid tied), however there are other questions.
1) Below 1000 watt the topology must change to make it economical.
2) Do you want sine wave inverter ( I assume so for >500W)
3) do you have batteries in system?
4) The difference dor the full range to 10000W inverter design is pretty large,fabrication, testing quality control, mechanical mounting