For the Floirence/Pisa stop try to contact Massimo- tuscany in tour. i didn't use his services myself, because he was not free the date we ask for, but he was nice and quick to reply to our questions.
For the Naples stop I would recommend giuseppe- sorrentotopcar. we used him for a Full Day Trip along the beautiful amalfi Coast and saw positano, amalfi, ravello and a lot of other villages along the Coast. He made a lot of photo- stops was nice, friendly and knowledgeable.