Monitoring service that can use DSC Internet and cellular

I'm looking for a new monitoring service. I've looked at ucontrol and
nextalarm, but I'd like to find someone who can use the DSC native
Internet communicators (TL-150/250), and also offer cellular (or
packet radio) for backup. I don't have the cellular backup hardware,
but would probably prefer something that's designed for the alarm
(like the DSC GS-3060), versus a phone line emulator.

Any recommendations?

Thanks,
Heath