Hi Solarhart is a large well known company but they may well use contractors to do the installation which may not be an issue if they are local?
The new generation ABB solar inverters are much better than the old PVI series but you really cannot beat the Fronius Primo for quality and reliability. I would definitely go the Fronius Primo inverter if it is the same price.
As for the panels I would ask them who manufacturers the panels for Solarhart and what are the warranty conditions? If you have a specification sheet for the panels feel free to post it up and we can see the details.