I'm familiar with the security business.
What you really want is for police to be called if your home is broken into, even if you can't be called. For this you need a monitoring contract, which can only be done through a security company (cannot be done as an individual).
You can use the other posts here to maybe find good open-source hardware. Security companies will generally not let you purchase hardware/software that you can modify. If there are any issues with anything, you have to prove you didn't have anything to do with the problem.
We don't even let customers have keys to the box with circuit board (called a panel) to change batteries.