Flood light pir

I am looking to automate my garage so that if the lights are on and there is no activity in there for lets say 10 min the lights will shut off. I have a decent size garage so the pir that i have found from sparkfun or places like that will only go to 20 feet and if I use them I will need at least 4 of them. so my idea is to use one from a flood light that I have lying around. and I am wondering if anyone has tore one apart nd got it to work with 5v or if I am going to have to rig it up to turn on an outlet with a old cellphone charger plugged into it and that signaling the arduino that there is power? I am new to using arduino so if I have said something wrong please correct me!

The PIR in the flood light is probably strongly connected with the mains.
I think you better buy a good quality PIR sensor. It could even be one with a 9V battery from a home alarm. That would be easier to connect to the Arduino.

would you know where I could get a good quality one at? cause the best distance have seen is 20 feet

I can't find a single PIR module, but only complete PIR devices. If they have a normal output signal (perhaps a relay output) you can connect them to the Arduino.

A few examples:

40 meters: http://www.voltek.co.uk/1804LR.asp?cat_id=130 long range: http://www.alliedelec.com/search/productdetail.aspx?SKU=70050679 long range: http://www.amazon.co.uk/SensIQ-Wall-Ceiling-Range-Sensor/dp/B002J8ZFQA/ 24 meters with 60 degrees: http://www.alarmcorp.com.au/catalogue/intrusion-products/internal-motion-detectors/pir-motion-detectors/product:ev635