A SIM is a SIM. It'll work in any GSM phone that's either locked to Cingular or unlocked. I can report that SIMs are quite durable -- I left one phone in my pants pocket and ran it through the laundry, after which the phone was never the same but the SIM still works fine.
Look on ebay. For use in the US, any 850/1900 phone will do the trick. You may see some phones that do 1900 but not 850, which I would avoid since Cingular has a lot more GSM 850 networks than 1900. Many GSM phones also handle 900 or 1800 which aren't used in the US, so they won't help either.