Walk the 463 steps that wind up to the top of the Dome and then choose the viewpoint that you enjoy most. Give yourself at least an hour at the top to really soak in the view and take pictures.
The wider angle lens you have the best shot of the city you can get (obviously!), so don't forget to pack it in your bag!
Kaard as he extends the telephoto to capture one of the smaller church domes in Florence from the very top of the Florence Cathedral.