GSM Card or USB GSM Modem for ASW 1700?

I am looking for a PCI GSM Modem Card for Asterisk or an USB version… Prefer PCI as I will be using a P4 system for a small office with 10 phones and maybe 2-3 concurrent call at any given time.

However I am looking for one that will support 1700 AWS for Tmobile / Wind Canada (Which is 3G)… All I found online is just 2G Modem…

Anyone know if this exist? If not could I some hook up a phone or smartphone to use as trunk?