Don’t know where you will be flying from, but you will probably get the most direct flights to Barcelona and Rome, although the airport for Rome (FCO) is about 90 minutes away. Research on cruisetimetables.com will show you that most cruises have a circular itinerary and board and debark guests in most of the ports. This can make embarkation less hectic, but you have safety drill announcements almost daily…but you may be off sightseeing when they occur.
If you want Spain and Italy you want western Mediterranean cruises. If you haven’t already, get a copy of Rick Steves’ Mediterranean Cruise Ports, read about them and decide which ones are the most important for your first time visit. My preference is for Eastern Mediterranean, especially including Venice.
You need to plan your excursions, or book cruise line excursions because you won’t find vendors waiting on the dock to sell you a tour. You know, I don’t think Ive ever been to a port talk on MSC, but any in Europe will not have shopping recommendations. No DI in Europe. Enough for now. EM