Best Security DVR CCTV Camera System?

So I have a friend who owns a small business and he's looking for a cost effective solution to a camera system. He wants to get a traditional security DVR and then set up CCTV cameras to that DVR? Does anyone have any suggestions for the DVR and CCTV cameras? The MOST important factor for him is RELIABILITY. He just wants something that will not break on him. Cost is also pretty important. Other then that, I await for your suggestions reddit!

We use Flir security cameras for our business you can refer them to your friend. They are Reliable and have quality products. Hope it will help you out. Good Luck