The Catholic Travel Guide
Self-Guided Tours: A Cross between Independent & Group Travel
There is an alternative to either the full-fledged guided tour and doing everything on your own: usually called a "self-guided tour" or "independent tour" or some similar name.
This type of tour appeals to those who do not want to deal with airline and hotel reservations or travel arrangements once they get there, but want more flexibility than a standard group tour offers.
You will need to adhere to the group schedule when traveling between cities, and although the groups are not Catholic you will be able to visit Catholic sites of interest, so long as you do your research in advance.
Be aware that cost will probably be more than a fully-escorted tour since you won't have the savings of group discounts for meals and attractions, but will be less than if you did everything on your own since the group rates will apply on hotels and transport. Plus you get to do things on your own without the constraints of the group. So you can eat in local restaurants, spend extra time at sites that are important to you, and move at your own pace each day (except when traveling)
Each company varies in its offers but basically you join a group with a specified itinerary.
We like the sound of Rick Steves' "My Way" 13-day Italy tour: you get air and hotels selected in advance, and transportation between cities as well. There is a local escort to accompany the group on the bus and give suggestions. Breakfasts are included but lunch and dinner are on your own.
Similarly, Gate 1 Travel has a "Florence & Rome by Rail" for 7 days that includes hotels, breakfasts and train tickets. Others, such as Perillo Tours or Trafalgar Tours have a mix of guided and self-guided touring.
Again, these are not Catholic tour groups, so there won't be an emphasis on Catholic sites but of course they abound in many European tours. Also you need to consider that although there may be other Catholics with you, there also may be those on the bus who may be hostile to the Catholic faith.