This is a question only you can answer, there are many companies and individuals which will be happy to sell you cameras and a recorders.
This equipment will allow you to see the views from your CCTV cameras and play back the recorded footage.
Simple what more do you need?
Firstly the most important is the quality of the recorded footage and still images the equipment produces.
Imagine you have invested in a CCTV system, and you become one of the 114,327 recorded theft related crimes (http://nzdotstat.stats.govt.nz Recorded crime victims statistics – unique victims). When you playback the video footage it’s dark and grainy and pretty much useless, you are only able to watching a silhouette carry your prize positions away.