We are using a DMP xt50 with network, cell, and dialer options. If you activate the cell option, you will incur an additional monthly cost. The network side is capable of SMTP messaging, but our is giving us fits right now. Also, it does not support TLS.
We have motion, drill/vibration, open/close, and other sensors all tied to that panel. It supports multiple zones, and you can daisy multiple sensors to single zones. There are also four configurable output pins that you could tie into an automation controller if you were handy with techy things.
You can find this panel used on many websites, but the problem will be getting monitoring. Most companies will not offer a monitoring contract unless they installed the product, or you have paid an inspection fee to verify that the product is working correctly.
Hope this helps!