I recommend staying at Fernandos place. His place has a good and creative spirit. He works as a journalist, so you should be independant enough. But still, if you need help, I am 100% sure Fernando would give you every information you need.
The location of the flat is perfect. The street is in a more quiet area, but you only need some minutes to be at the Centro Storico. Also within a short walk you can reach nice restaurants and supermarkets.
You have your own bathroom and can use the kitchen if you want. The room is nice and cosy, I had a very good stay at his place.