I am leaving T-mobile and moving to Verizon. I am going to get the BB 9930 and the I4s. Should I buy both phones with plans or should I buy 2 phones with 1 plan and switch them out? How easy will it be to switch out with Verizon? It's easy with T-mobile due to the sim card. I could also use the I4s for personal and the BB 9930 for business. Anyone have any recommendations either way? TIA