My two cents:
Honda's part and dealer network is outstanding. I can get parts for one of their models almost anywhere.
Yamaha's is less, but there is at least one place I can mail order and get parts from.
Champion, I order parts from them. Their CS is excellent.
Other brands are random. You might find that no parts are available for that model, or the same model has a new generation with improvements that are not documented.
In general, 10 years from now, the Honda/Yamaha will still be fixable. The Champion likely will be fine as well. The no-name brands will long since have been sent to the scrapyard.
The gist of it: If money is an issue, buy a Champion 2000 watt model. They are a little bit more than the no-names, but will do the job well.