Iphone External Screen Changing Cell Provider Need Info?

Changing cell provider need info? - iphone external screen

Hello,
in turn my cell phone provider AT & T to another person. I am NOT this:

AT & T / Cingular
Verizon
T-Mobile
Nextel
Sprint
-Virgin Mobile
"Hello

Taking into account the following:
-US Cellular
Unicel --
Boost Mobile


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I need a cheap phone, the many functions like a camera that has a good screen, if I do not want a flip phone (with external display) or a telephone-style bar. I want a smartphone and not get the iPhone! I need a phone for under $ 200 plus $ 100 if possible. Thank you.