I have a Huawei E173 HSPA USB stick. Works like a charm. I would not recommend buying any sort broadband modem from a cellular phone provider in the U.S. because it would need to be unlocked. Try a reputable seller on EBay, perhaps? Make sure that "unlocked" is explicitly stated somewhere in the item description.
If you have a Movistar Chip, the profile details are the following:
APN (Static): internet.gprs.unifon.com.ar
Access #: *99#
User: internet
Password: internet
I don't know how good of a provider Movistar is in Cordoba, but it certainly works quite well in Capital. It's 10 pesos for 1 GB a day, which is not ideal if you plan on downloading large files. However, for general e-mail sending, Skype usage, website editing, uploading (business-related tasks), it's great. If you were to pay 10 pesos every day, it would be about $74 USD per month. Not a bad deal, in my opinion. Shoot me a private message if you have any questions.