I currently have the free 200 MB monthly on T-Mobile on my iPad Mini 2. I would like to buy the new 10.5" Pro, and be able to transfer my SIM card over to it so that I can continue to get the free 200 MB of data. Is there a particular model/carrier that I need to buy? I've read that I shouldn't buy the ones with the Apple Sim cards, and buying a T-Mobile iPad Pro would not work as well, which is a bit confusing. Some have suggested that I should buy the one that comes with the ATT SIM card. Any accurate information would be greatly appreciated. Thanks!