Finally, got some time to install my DIY system. I went with Reolink 5Mp bullets. Had to string Cat5e/6 cable to replace the old Lorex proprietary cables and add a POE switch to plug the cameras into. I have cameras installed and will add 3 or 4 more. Downloaded a surveillance app called Blue IRIS and have a dedicated PC to act as my NVR.
Now I can upgrade any component (camera, hard drive, software, etc.) and not be stuck with a brand.
The learning curve is a bit steep with Blue Iris but now I am getting the hang of it. The Blue Iris program is quite powerful and very configurable for each camera. It is a CPU hog, so it is best to have an i5 chip or better and not be running other stuff on the same PC.
What I like is to be able to create 'motion zones' and trigger the recording only when those zones show motion. This allows you to 'paint' out the bushes because of wind, and other things that move in the background such as cars on the street, etc.