I have two 5s iPhones on a 2 year contract with AT&T that expires this month. I have unlimited data grandfathered and since about two months ago I also have unlimited talk and text. My monthly service charge for the two 5s phones with unlimited everything is about $140. Could anyone tell me what my best upgrade option would be? AT&T Next? Another contract? I like to keep my phones for 24 months and upgrade when a new "S" model comes out. Thanks.