"We don't need no stinkin badges"

Both the DSC and the Honeywell talk the same to just about any central any where!
I too know for a fact A#t does it and I would assume Bay does too...
Now, are you going to let them adjust the programming? I wasn't clear with your post when you said "they'll have to change my control panel" are you talking the board or the programming?
Programming would be required (phone #s, account #, communication parameters, etc.)
If you have no luck with them, I'm sure you have some local smaller established co out there that could figure it out

Jim