The Liftmaster Elite 8500 is an excellent opener to use with the Alarm.com home automation package. I recently replaced my aging garage door opener with one of these and it works perfectly with the ADC account. I couldn't be happier with the performance of this unit and how easy it was to install.
I picked up the opener for under $300 here: http://www.ebay.com/usr/opendoorllc
Following is a video howto that walks through the installation:
It took me about 3-4 hours to remove my old garage door opener and install the new Liftmaster opener following these videos.