What questions should I ask the supplier when looking to buy an RCAC?

What questions should I ask the supplier when looking to buy an RCAC?

The below are a list of some key questions to ask

Are your installers fully insured ARC licensed technicians? 
How long have they been in business? 
Can you provide me with references in my area? 
Do you provide maintenance services? 
Do you do a site visit? What does this involve? 
What documentation will I receive before and after the installation? 
How long does the installation take? Will it be finished in one visit?