Need help on finding the best laser sensor

Greetings,
am searching for a sensor that would i want to use it as a motion detecor.
the Idea is to detect any motion in an area of 10 meters long and 2 meters hight i.e straight and vertical.
much appreciated if any can advice me with the best sensors that can cover this area.
regards.

http://lmgtfy.com/?q=best+motion+sensor

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