Hi,
I am going on the tour with one of my friends on the 19th and I was curious did anyone book tours to the Vatican, Uffizi, and the Last Supper in Ufizi? If so, what times did you go and did the times conflict with the any of the contiki tours?

I am not on your tour, but when I went on Simply Italy in May, I prebooked Uffizi for 1:45 and Accademia(where David is) for 3:45. I didn't prebooked the Vatican. I am not sure if I was lucky, but I didn't stand in line to get into Vatican. I got there at 12:30, and got right in without any line. Those times didn't conflict with anything. For a while I thought I would have to take public bus back to the hotel in Florence since Contiki bus left from central Florence at 4:30. But I got in to Accademia, saw David and got out without seing much else and still had time to make it back to the bus.
For the Last Supper, I didn't book in advance because I wasn't interested in seing it. If you do want to see it, you should definetly book in advance because it's almost impossible to get in(although, 2 people in my group got lucky and got to see it). Can't remember when the bus left from central Milan, but I think if you book it for 1 or 2, you should be fine.

Thanks!