You’re never going to get an inexpensive international plan from a US carrier. Your best deal will be to buy a prepaid SIM card when you arrive at your destination. There is a (San Diego based, coincidently enough) company that sells an international roaming SIM card, but their prices, while better than the US carriers, are still very expensive compared to buying a prepaid SIM card in-country. http://www.telestial.com/international-sim-cards.php
So that’s the SIM card half of the equation. As for the device, most smartphones have a tethering option built in, where the phone acts as a personal WiFi hotspot for you, while accessing the cellular data network.
One important note: you can only use a different SIM card in a phone if the phone is “unlocked.”
Many wireless carriers subsidize some or all of the upfront cost of a cell phone by building that cost into the monthly subscription. So when they say “free phone with 2 year contract,” the phone isn’t free, its cost is just being amortized over the two year subscription period. And obviously they don’t want people to get the free phone, cancel the service, and switch to another carrier. So to prevent this, the phone is electronically “locked” to not recognize SIM cards from other carriers.
So you need to figure out whether your phone is locked or not. If you have had the same phone with the same carrier for 2+ years, many carriers will unlock the phone for you for no charge.
There are more clandestine ways to unlock locked phones, but let’s not go down that rabbit hole just yet.
