Don't know about a CAB, but the settings for T-Mobile data can be manually input. Here's the link for the settings.
http://support.t-mobile.com/doc/tm21...NV-tPdlvVlSDs?
If you're running a ROM with Manila, go to the Settings tab, Wireless Controls, Menu button, and Connections.
Go to Advanced, Select Network, and then press the New button.
Type in a name and press the OK button. Then press the Edit button.
Hit the New button on the bottom, enter a name for the connection, and under Select a Modem, choose Cellular Line (GPRS, 3G).
Then enter in the settings. Good luck.