Your fist question is to decide what your aim is, is it self-protection or protection of property or a combination of both? CCTV cannot and should not replace an alarm system. An alarm system is designed to reduce false alarms and give you advanced warning, a CCTV system is used to give you a view and record your environment, I cannot stress this enough, don’t try to use a CCTV system as an alarm. Banks don't expect their CCTV system to replace their alarm systems, and neither should you.