And which networks are going to carry them. In this area, you need either US Cellular or Verizon for good coverage.
They'll be unlocked GSM only. So ATT, T-Mobile and some of the discount GSM carriers.
> coverage
I have T-Mobile, which is fine in major markets. When I traveled to Iowa I only got a signal near the Interstate or in a larger town (read country seat.) In the very small town I was visiting I barely got one voice bar only if I stepped outside and raised the phone up, arm's length, over my head. Verizon is the only way to go out there.