[Bossman]

As has been posted above, as long as your phone has the 1900 band, which both of your phones do have, you will be fine. Tmobile payg uses the 1900 band exclusively. So, IMHO that will be the better choice. Of course, your phones have to be unlocked. Now, if you were asking about roaming, you have to check with your carrier if they have roaming agreements with any of the carriers here.