A few points that you'll have to consider first.....
- If your phone is not unlocked, you won't be able to use any other SIM cards.
- Depending on which network you're with and the type of phone you're using, it may or may not work in Europe.
- It may be difficult to top-up PAYG cards once you've left the country of purchase.
is there any operator that sells packages that work in various countries?
Yes! You could have a look at some of the travel phone firms such as Roam Simple, Cellular Abroad, Telestial, Mobal, EuroBuzz, One SIM, Max Roam or KeepGo (there are others). Data services tend to be on the "pricey" side with these, but basic voice and text is usually quite reasonable.
As someone else suggested, you may want to speak with the CS staff at your cell network, as using their international roaming plans may be quite reasonable (depending on usage).