I own 2 iPhones (5S and a 7). Will be in New Zealand in a couple of months. While there, I intend to purchase a local sim card with data access. If I get such a sim, can I place it in either phone or will be be "locked" to the first phone i put it in? Both of my phones are unlocked. Also, will I get a new number while in New Zealand with one of these sim cards?