Florence (Tuscany) offers infinite possibilities for any type of accommodations. The tourism is highly considered wherever in Italy, but the Tuscany and especially Florence has an amazing plethora of choices.
Almost all the luxury hotels are located in the city centre, but you have few exceptions, with hills hotels on the way to Fiesole, or close to the famous “Michelangelo square”.
The nice thing is that you may find very nice hotels even at low rates; in fact the general level of a regular 3 stars hotel is pretty high for the standard.
Italian collection suggest you a stay in the city centre, for a night romantic promenade or a daily tour in the shopping district.
However remember: all around Florence, you have the marvellous Tuscany countryside (Chianti, Val d'Orcia), and beautiful cities such as Pisa and Siena. Don't' miss it!