SKU version explanation and rom update

[Guest stalkerzone]

My phone is a Qtek 8020, and I have the choice of 3 different SKU versions of the rom. I know which one i should choose but i would like to know a little more about the difference between the versions, and why they exists as several versions.

Also, what would happen, If i where to take the wrong rom. Would my phone stop working, would i experience network connections problems, or anything else.

Please, tell me all you know :)