Middle East - Pre-Paid SIM Card in Jordan? Best & available at Airport?

Folks -- Mrs Flies and I are making our first trip to the Middle East next January. We are flying into Amman (Queen Alia airport) and driving to an archeological dig site. I've done some searching about pre-paid SIM cards I could use in my unlocked quad GSM phone and have not yet found one that appears better than the other. We would use the airtime to call internally within Jordan and back home to the U.S. -- not a lot, but, occasionally. We will be there for two weeks, so I don't need an account. I have purchased prepaid SIMs in other countries and have been generally satisfied with the service and rates, especially for only a couple of weeks. Because I have an unlocked phone and because of the enormous cost of international roaming, that option is a non-starter.

I would be grateful for any recommendations and I would also be interested to know if there are kiosks at the airport outside customs where I could buy the SIM.

Thanks very much!