"Security" is a word that means many different things to different folks. While the technical part isn't too difficult, there are a few things to consider:
Various insurers, and others, have their requirements before they will "approve" the system, or give the discount;
System components are often brand-specific.
False alarms are far more to be avoided than the system not being "sensitive enough."
Finally, a chat with your insurer may be in order. Let there be a loss suffered- even years from now, long after you've stopped maintaining it, and you're sure to be among those sued.
While the trade press occasionally gushes about all the business in "security," there is a reason alarm installers earn less than electricians!
