I have an original iPhone that I may or may not be keeping. I am trying to downsize my expenses, and have been considering changing carriers to T-Mobile, either PrePay/FlexPay or normal contract. If I go FlexPay or normal contract, what is a good basic phone (cheap) for use on their service? I may keep the iPhone and jailbreak/unlock it too, or I may sell it. I want to keep my number, so I can't just buy a prepaid SIM card (or can I?). So many questions, so few answers.