I currently have a family plan (3 lines) on tmobile and I'm trying to get the 4s with at&t. If I reserve 2 4s on apple.com/retail can I also create a family plan with at&t at the apple store when I go tomorrow? I called a couple of at&t store to ask if there had any 4s left , they said no and they didn't know when they will get the next shipment. I live in NYC. Thanks.