Video Home Security Recommendations????

My client is buying a fixer down the street from where she lives now. She wants to downsize and totally renovate the house, while living in her present home. The houses are on street with lots of foot traffic. The next door neighbor is a friend who is home a lot--so she can kind of keep an eye on the vacant house. What say you all? Should the buyer consider a security system? Should she go video--with Comcast or Verizon?