Another option is Konnected. I use their original Interface kit. There a few threads about them.
I only got one 6-zone unit and their equipment can't use Zone 1 of a Vista 15/20 panel so I am stuck w/ only 5 zones. With enough zones, you can arm/disarm your existing alarm panel but I haven't gone down that road. It requires programming of your alarm which is supposedly extremely difficult with the base model alarm keypads I have but is probably easier with the Tuxedo unit you have.
