I'm buying a new unlocked phone in the next few days.

I would like to buy an unbranded one but haven't found a reliable shop that will ship here. Does it make any difference aside from the logos if I get ATT, T-MO, Rogers, etc?

Thanks.

Depends which model you want.
And where you are and what carrier you are using.

I'm looking at an 8900 and the carriers are all GSM and 3G only. I don't need 3G because I can use wifi and already have a 3G phone.

Good, as the 8900 is not 3G.

Choose the carrier first, then the model BlackBerry. I think the 8900 is a great BB.

Buying a phone from the carrier with contract is out of the question. It comes out to be about 200 dollars more than it would cost me to buy an unlocked one from an import shop.

Surprisingly, the 5G BIS plan is less than 30 dollars including all taxes! And now we know how they can do that...