I will preface by saying hae no info relating to your question. But without more info do have a suggestion/comment which might help you answer our own question.

You might check this site and Trip Advisor under the topic of "italian traffic tickets", "Rome traffice", problems with renting a car in Rome", etc. You will find Rome is a horrific, terrible, nightmarish, problematic place to rent a car if you are staying in Rome. We suffered by attempting to return a car which resulted in numerous runa arounds with one way streets, horrible traffic, crazy, narrow streets and 2 traffice tickets arriving on our doorstep after 2 attempted credit card charges by the Rome municipality. So I would do anything but rent a car for staying in or driving in Rome.

"Rome hotels by FCO" on this site would/might give you recommendations that you are looking for.

I would consider getting a car an driver if, as you are 7 adults, want to get around in a vehicle.

I agree that a car in Rome is a HUGE liability. Train and buses are such a great mass transit transportation option that renting a car could be the most commom rookie mistake for Rome-bound first travelers. BTW, you do not tell the rental car company where are YOU going to drop off the car. They give you choices according to the DROP off city. Typically, when you select the drop off city, then the acceptable drop-off points are laid out for you to choose from.

I would suggest you use a shuttle service such as Roma Express, etc... to get from FCO to Rome. Rent an apartment in Rome, then use the same shuttle service to be pick-up at the apartment and drop-off at the port in Civitavecchia. That is, if you do not want to use the train (with 7 people/suitcases, I would opt for the shuttle service). BTW, if using a shuttle service-- the more, the cheaper!

Again cease and desist of the crazy idea of renting a car in Rome unless you are picking the car at FCO and heading somewhere else than Rome. Your research efforts are MUCH better spend in renting an apartment. Apartments in the Vatican area are cheaper, larger, and cleaner. Apartments near Piazza Navona are more convenient (often plumbing is an issue!), apartments near area Campo de Fiori are a great value. I have used vrbo.com and holiday-rentals.com to rent apartments in Europe and been extremely pleased.

Another tip?-- get the ROMA PASS! For 25 Euros/pp you get 3 unlimited days of local train/bus transportation, and free entrance to 3 out of 25 listed museums including the Coloseum and the Roman Forum. This will save you serious waiting time on the HUGE tickets lines (show your Roma Pass- go in using a special entrance). One of the best tips I ever got on this forum! Roma Pass can be purchased in Tobacci stops (small stores), I got mine at the Rome Officce of R-Tourism at the Termini Train Station (second floor near Platform 25).

Have fun- I am heading out to Rome (again!) in November!

I didn't read the OP as wanting a rental car for use in Rome where a rental car, as you say, would be a huge liability and totally unnecessary.

OP, I would start by phoning Hertz, Europcar, Avis, etc., and telling them what you want in terms of pick up and drop-off points or use the websites or combination of both. They will know the names of their drop-offs near the port.

Forgot to add, there are vans which hold 7 but from experience they have limited luggage room so unless the 7 adults are packing very, very light, you may be better off with two cars. Even then, European rental cars tend to have less luggage space.

I'd consider spending your 4 days in Rome, going straight in from FCO via train or taxi (around 50€ flat rate).

Never mind that renting a car is a hugh liability in Rome. think about parking, which is almost non-existence.

We didn't even take the Metro or bus. We walked everywhere. Juts make sure you pick a hotel that is central in location.

We stayed at the Hotel Quirinale which is in a great location. There are many hotels around tehre as well.
We are 5 blocks form the Tivili fountain, 2 blocks amd the art Gallery, and many churches. 2 metro stosp from the spanish steps (we walked) and 15 blokcs from teh Coliseum.

We took a cab to the Vatican. It was early in the morning, no traffic and the 6 of us piled into 1 larger cab (prebook with hotel). The fare was only 12 euros due to a total lack of traffic as it was real early (we arrived at Vatican at 7 am). We took cab from Vatican to Pantheon, about 10 eruos. We walked from Pantheon back to hotel.

Many good local restaurnants clsoe to the hotel, reasonably priced too. If you want safe North American Food, McD is 2 blocks away, and O'grady's Irish Pub a block away.

One thing about Rome, or most European major cities for that matter, be very aware of pick pockets. They can pick out tourist as they really stand out and easy picking.

Paris and Rome are probably the worst for pick pockets

Thank you to all for your helpful advice. We've managed to book 2 cars from FCO, will travel to Isernia for four days, take NCL Epic for 7 days and finish up with 3 days in Rome. I have two more questions to ask. I have booked Hotel Amalfi for our 3 nights in Rome. Reviews on TA looked quite positive. Comments? Also, our cruise stops in Marseilles. I've heard there isn't much there. Does anyone have any suggestions? We'd like to find a nearby winery where we can relax, drink wine, eat proscutto, cheeses, etc etc. Any suggestions? Thanks to all in advance!!

We're also traveling on the Epic, but next June. If you haven't already planned your day in Marseilles - we are doing a private tour with www.provence-connection-tours.com We chose the full day tour - I'm not sure if you could customize a day with them to a winery, but I'm sure you could contact them with your ideas and see what they say. They were very responsive with their emails to me.

Where did you end up booking your rental car? I'm looking for a one way rental from Venice to the port - do you have to return to the train station or did you find a place to return directly to the port before the cruise? I thought Hertz had a location right at the port. We had looked into a 9 person van for the 6 of us. Hopefully that will work out!

Enjoy the Epic! If you get a chance, maybe you could post a review when you get back - have you been on cruisecritic?

In Marseilles, you can easily catch a bus to (beautiful) Aix and spend the day. Don't know about a winery there, but lovely cafes - right out of a painting, and nice markets.