You need the iPad 2 WiFi+3G GSM (AT&T), the Verizon model won't work. They are still scarce here so you will need to get in line about 9:00a and wait to see if they get any stock that suits your needs.
Are you sure about this information because I am about to ask someone to buy it for me and ship it to me overseas and I want to make sure that If I get the iPad 2 WiFi+3G GSM (AT&T) that it will work because someone asked in the apple store and they told him that it is locked and will not work overseas
The US iPad Wifi + 3G bought from Apple or ATT is NOT network locked.
Stay clear of Verizon however as these have CDMA and not GSM radio.
(Effectively if you were to buy one from them you would simply have an overpriced WIFI model internationally)
There are just a very few places where the iPad is being network locked and that includes surprisingly the very competitive UK mobile services.
Specifically Orange (UK) is one - They block there subsidised iPad offerings for a minimum of three months then charge £20 for un-blocking !