Personally, I would go back to Florence, loved it. If you get a hotel room ahead of time, ask them to get the tickets you need to the places you want to go. If you love art the Uffizi is great as is the Academia, but then we loved the Pitti Palace too. I really do not see how you can do it in a day, nor would I want to. The food and the stores are great too and everything is in walking distance.