I use these cameras at work. http://www.foscam.com/
They are IP cameras. I went with wired to a hub. I can access the cameras from anywhere and see what is going on. You can then use BLUEIRIS to record to a PC with a large drive.
Also use IP Cam Viewer on Android or tablet to see what is up at the shop. You can also listed and talk back and forth, but that does not work that good.