For the Tuscan part of your trip, you may want to consider hiring Luca Garrapa, the owner of hillsandroads.com He's driver, guide and historian all in one. Wonderful man. Very friendly, great English. He gets rave reviews on this board from people who have hired him, like me.

He could show you around Tuscany which is what he did for us for 1.5 days. He may be able to pick you up at the airport and drive you to your Tuscan destination, making stops along the way in Umbria (Orvieto is especially nice). That would make for a wonderful first day when you're jetlagged. He picked us up at our Rome B&B and drove us to Siena, which is near his home, with lots of great stops en route. We were on a tight schedule, too, and he helped us see a lot in a short period of time.

Take 2 on Luca: http://www.hillsandroads.com/