i guess this is the snobbish answer, but don't do a guided tour of europe. you'll regret it assuming your main reasons for travelling aren't getting sh*tfaced in "irish" bars. (touristy parts of europe have irish pubs that basically cater to obnoxious english-speaking tourists). you won't get a good feel of the environment/culture and you won't be on your own schedule. go with a friend (or ever alone) and meet up with the other travellers in the various hostels in which you'll be staying.