I am not a security system expert, but you have a lot of choices here. You have packaged systems, modular type systems that are maybe a small package that has expandability, or even build your own system from your own components, and integrate them with some kind of autodialer, or in your case one that uses cell phone technology instead of a land line. Depending on how much you want to spend you can even call the system from remote location and listen in or watch if you have video coverage, or even remote control items at the site, while connected to the system.
Of course just having a few Doberman's roaming the place will help, but it takes money to feed and care for them too:happyyes: