I don’t think there is one right answer. First, you have to see the local installers near you, then consider the size of the installation, and whether you want future expandability. weather you want a battery installed to utilize the extra power at night rather than selling it a stupidly low price back to the grid, whether you want a smart energy monitoring system installed to do things like automatically telling the heat-pump to heat the water when excess power is being generated. Have a look at the local installers, then have a look at the reviews of those, then get quotes from those companies. If you give the community a rough idea of where you live, some people local to that area might be able to give advice on who they used too.