I am prepping for my vacation to Italy and Greece next month and I had a few questions. I am an AT&T customer who did an eBay unlock (confirming through iTunes) and need to know what I can do to get ready to take my iPhone 5 with me for calling. My main concern would be data, as there a few games I REALLY need to follow while I am over there. What carrier(s) do I need to look into before I go and can I buy those sim cards now and not have to worry about it upon arrival? Let me know as I am completely clueless right now.