Hi,
Most of our customers here have SMS email gateways, so we just format the sms notification a bit different than the email notification. One neat thing we did is that we used the notification scripts to determine if the "Notification Data" field of SANM contains a email address or mobile number and based on that the alert will be processed accordingly. Or you can create seperate SANM policies that use seperate AlarmNotifier Instances one for email and one for SMS.
You just need to determine the transport mechanism for sending out SMS's within the organization and modify the Notification scripts.
Regards.