It's not that much more to travel in comfort and be picked up at the ship. Last year we used Stefano Costantini, he was great and I highly recommend him. I don't have his web address but you can contact him via email and ask for his web address:
He picked us up at the airport in Romeand took us to the hotel, took us (a group from the boards) on an Evening Tour of Rome, tpopk us to the ship and took us to the airport after the cruise was over. Very reliable, always on time and a pleasure to deal with.
Enjoy your cruise.