I live in the US, we have Verizon Iphone 4 and 4S. Will these work in Europe? I realize I may neeed to get a plan for calling but the phones will work?
If you have/use Google Voice (or go ahead and sign up for it) you should be able to use the Talkatone app on the iPhone to make (and I believe receive) calls using Google Voice via WiFi. And you can use it (essentially Google Voice) for text messaging as well.