A:AnswerI don't think the model of phone matters really. You just have get the card, pay activation fee, and connect through a network. Like you can go to a Starbucks and use their Hotspot or use the wifi at a friend's house. This helps for the process to be faster. I hope I answered your questions and I wish you a safe travel back to the US. :)
A:AnswerYes, assuming that the device is not Carrier Locked to any Cellular Service Provider.
Compatible with all GSM unlocked devices unless otherwise stated on the product packaging and/or as stated on the AT&T websites.