Hey,
What you nedd is 4 IR cameras and a DVR card in your PC then The Card will reccord all the occurances on the camera in the pc for this you will have to allocate a special drive... I reccomend you to use h.264 technology.... new and the best..... It will take 100.74 MB per camera per hour... so proper allocation will be needed....
For More information you can download my company's profile.....I have attached it... all the contact details are in it along with a basic introduction of my company... contact us... may be we can help you get a cheaper and effective system....take care
