http://forum.homesecuritystore.com/
All you need to know. Monitoring available for $8.95 a month.
I have a Honeywell (Ademco) Vista 20P with 6270 touchscreen (mostly wired, but a few wireless) that my local security company installed (reasonable $$) and currently monitors for $19.99/mo. My wife loves it.
Homeowner's insurance discount is $250/yr so it pays for the monitoring.