Can anyone provides us with advice on a

I always use Hertz . They have several offices around Rome and at both airports. There is also an office next to Rome Termini station . The may not be the cheapest but I find them reliable and have never had the scam of billing for supposed damage to alloy wheels or scratches on vehicle after return of car . This is a common occurrence in some of the lesser known companies in Italy and it is very difficult to refute the evidence once you have left the country .
The money is just taken from your card.

Thank you for the advice. It's good to know.Cindy