Arduino Accident Reporter

My project is as follows: I have been ask to provide a way to mount a device or box in this case to golf carts that run in a warehouse under 24 hours with wifi. I need to sense when there is a crash or wreck involving anything that would cause damage to the golf cart or other object. Could be used on vehicles with cellular as well. Then over wifi or cellular, a choice but capable of both, would email or text message a person of choice, I also need a user adjustable sensitivity adjustment. I am using a Arduino Yun, 3 Axis Accelerometer, a piezoelectric disk in combination with the Accelerometer. I need this to communicate over both wifi and cellular and made to be a choice of which to use. I too need advice if the hardware listed above is indeed what I need or please make suggestions for hardware. I will put all of this together, I just need the program written to accomplish the above. This would be a one time hire. I need to know how long this would take and cost. Thanks, Dale