Firstly congratulations on the wedding, hope you both had a fantastic day.
Both Florence & Rome are very easy to get to using the Italian trains. Florence goes via Pisa, and the station is a couple of miles away from the drop off point, but Rome is very quick & easy. The train stops in 5 places around Rome, the first being for the Vatican, the last being in the centre of the city.
The prices of these very clean & comfortable trains is a fraction of the tours costs (e.g. Roma €4.10e/w), so if you are planning on doing "on your own" tours, we would certainly suggest you consider the trains.
The Italian train site is http://www.trenitalia.com/en/index.html
, and gives times & costs, etc. Note though, the ES (€8.62e/w) & IC (€7.97e/w) trains are slightly more expensive
Hope this helps, speak soon
Katrina & Alan