Italy transportation

1. A driver from Rome to Amalfi will cost you around 400 €. Is that ok for you?
2. Does "a tour of the area" mean explaining the stuff you will see while driving for 170 miles in two different Regions? If so, you'll have to pay for a guide on top of the cost of the driver. If you mean Pompeii, you can just hire a licensed guide at the gates.
3. If you will need a car in Tuscany, why renting it either in Rome or Naples? Both cities are quite difficult to drive around, and they have their ZTLs. High speed trains are faster than cars, and discounted tickets purchased in advance may be cheaper than gas, tolls and the cost of the Rental.
4. If you think you can memorize the ZTL signs and you can avoid driving past them, get the rental car in downtown Florence. Otherwise get it either in Florence Airport or in Chiusi or in Orvieto.

Have you pinpointed all these places on a map? Or on a mapping site like viamichelin.com?

We rented several times in Orvieto to drive through Tuscany and Umbria. It worked out well for us each time. I would not rent in Naples. It was chaos for us driving and picking up the car. That is the only time that my husband said not to rent there again. Usually we rent in Bologna because I spend half the year nearby.

If you are staying in Amalfi before heading to Tuscany, I would consider renting the car in Salerno. Avis-Budget, Europcar, Hertz, all have offices in Salerno. Actually I would send the driver to Salerno, pickup the car, and drive to Amalfi to pick up the rest of the party (and the luggage) before driving to Tuscany.
I generally use www.AutoEurope.com (a broker) to rent cars in Europe including Italy. They work with all the rental companies above and usually you can get the car at a discount compared to going directly to those companies.

If driving 5 hours (mostly freeway) to Tuscany is too much, then the best option is to take a fast train from Salerno to Florence and renting in Florence. It also depends on where in Tuscany your destination is. Tuscany is a big region, as big as the State of Massachusetts.

Your trip sounds nearly identical to ours. We're flying into Rome, but with just one night there until we head south. Next is Sorrento, then Amalfi, then a week at an agriturismo in Tuscany, then a couple final nights in Rome. We are using trains to get from Rome to Sorrento, a private driver, at about 140€, to get to Amalfi after Sorrento, then a private driver at about 100€ to get from Amalfi to Salerno, where we will rent a car at Avis for the drive up to Tuscany. We will keep the car to drive to Rome after Tuscany, but return it at the airport, then use car transport (arranged by our Rome hotel) to get into the city from the airport.

I explored taking the train from Salerno up to Chiusi to rent the car there for our week in Tuscany. We would then return the car there and use the train to get to Rome. However, the train ride up to Tuscany takes much longer than driving. Having a car to make the drive up allows us to be on our own schedule and stop on the way if there's an interesting place we want to have lunch or explore (I'm thinking Orvieto).

Roberto, I'm curious as to why you would just "send the driver" to Salerno to pick up the car, then have him drive back to Amalfi to get the rest of the party and luggage. Why not have the entire party go to Salerno to get the car? Is there a route up to Tuscany from Amalfi that's easier/faster than the route from Salerno?

I think that someone else also recently asked this question and the consensus was to train to Naples and have the driver pick you up there. We did this just last month and arranged the driver through our hotel for €120. You don’t really need the car in Amalfi. We picked up our car in Naples and drove to Tuscany after the AC. I agree with others here that Sorrento is also a good choice. The drive from either Sorrento or Naples is about the same time as taking the train to somewhere in Tuscany and then getting a car.

However, the train ride up to Tuscany takes much longer than driving.

Where did you get this info? Sure, driving is cheaper if you are more than 2 people, but saying that the train takes "much longer" is quite wrong imho.

The drive from Salerno to Chiusi takes 4 hours, plus stops. There is a direct train going from Salerno to Chiusi-Chianciano Terme in 3 h and 20. It takes between 3h15mm and 4h40mm if you have to change trains in Rome.

The fastest train from Salerno to Orvieto takes 2 hours and 50, changing in Rome. By car it takes around 3 hours and 50, plus stops. The problem with renting in Orvieto is that only Hertz has an office there and it's closed on Sundays.

I would have asked a quote to be taken by car from the Amalfi Coast to Napoli Afragola station, that is in the right direction if one is going north and where there are trains departing to Orvieto that take less than 3 hours and half. Of course this way you would have missed the opportunity to see Salerno, that's quite nice for a middle sized town.

You're right, Dario, I shouldn't have said that the train takes "a lot" longer. In our case, on the day we are traveling up to Tuscany, there are many train departure choices all day long to get from Salerno to Chiusi. There's one departure time that has a travel duration of only 3 and a half hours but it departs Salerno at 5:15 a.m. There's another that's 3 hours and 37 minutes, but that one too is pretty early for us, departing at 9:13 a.m. All the other trains that depart between 9 a.m. and noon have travel times ranging from 4 hours 14 minutes to 7 hours 24 minutes. And everything in between. For us, a factor to take into account is that once we arrive in Chiusi, we still have a 45 minute drive to our agriturismo. We can drive all the way from Salerno to our agriturismo in about 4 and a quarter hours, so for us, the drive made sense. I like the flexibility it gives us.