Is a bit of a minefield butterfly, and can be quite expensive. Some of the cameras inside are not that good. Ones with a higher TVL would be better but more expensive. Thats TV lines. Then there is the question do I want the camera hard wired or wireless, and the wireless can have a limited range. Sorry I cant be more helpful but not to well informed with what you are asking. Do you need to have a camera one. The wired ones need to be connected to the mains via an adaptor ( voltage regulator ). Usually 12 volts.