We will land at Rome FCO airport at 6am. We need to get a train to Florence then. Are there direct trains from the airport? Is it cheaper to buy tickets online before the time? We do not know how long it will take us to get suitcases and get through passport checks etc, so are hesitant to buy tickets before the time and then possibly miss the train.
You would need to take the Leonardo Express to Rome Termini, and then change to a fast train to Florence. They are marked as Freccia trains in the following link. You can choose the particular date you are travelling and compare prices.
https://www.lefrecce.it/B2CWeb/search.do?parameter=searchOutputViewer&cFID=MvfV58pPfCfq
For the fast trains, buying ahead of time gives you quite significant discounts as compared to buying on the day. However, you have a valid concern of plane delays etc. Maybe someone else can help with some suggestions.
There are 2 direct trains every day, but more than 1 per hour if you change trains in Rome, either at Termini or Tiburtina. Since you have identified the risk of advance purchase, just buy when you arrive. The first direct train is at 11:08, but arriving at 6 am, you could be in Florence an hour before that direct train even leaves the airport, if you just take the first available train after you get your luggage.
Even 3 months out, the cheapest nonrefundable SuperEconomy ticket is 28 EUR vs 55 EUR bought when you arrive, so the discount is not that big. Is it worth 27 EUR to sit around the station for 3 hours? Your choice.
There is one at 11:08. All others in the morning require a change at Roma Tiburtina.
www.trenitalia.com
enter from FIUMICINO AEROPORTO to FIRENZE SANTA MARIA NOVELLA.
Buying in advance saves money on supereconomy and economy fares, but if your plane arrives late and you miss the train you book, you lose all your money. It’s safer to buy at full price at the airport station when you arrive.
If you decide to use a Regionale train to connect with the fast train to Florence at either Termini or Tiburtina, be sure to validate your tickets prior to boarding the train or you'll risk hefty fines which will be collected on the spot! Also note that there are two Regionale trains serving the airport. Be sure to board the right train!
A question: have you considered flying instead? Flights are relatively cheap in Europe and you may get there faster.
Flying to Florence from North America involves a plane change at some other European airport, with the subsequent wait time. I take a direct flight any day and take a rail connection after landing. The train puts you in the city center, while at the airport outside of town, you have a bus or taxi ride ahead of you to get to the city center.
The OP says that is arriving at FCO at 06:00, that presumes the air ticket was purchased already, therefore flying directly to FLR is probably not an option. From FCO to FLR there are only 3 flights a day all with Alitalia. The first one departs at 10:30am. By that time, with a 6am arrival at FCO, one could be in Florence already using the train.
Thank you for the input everyone. We have bought flights months ago and will fly into Rome. The connection flights from rome to Florence is quite expensive ( a lot more expensive) than the trains, as we are from south africa and hence have a very weak currency. So we will probably take a train into Rome and then a high speed train from there. Thank you once again!!