We've been reading about some professional outdoor photographers who are using the EOS rebel camera rigged with an external motion sensor and slave flash.
Here's the test setup in our workshop-it worked!

The EOS rebel can be obtained cheap on the used market and works well with no modifications due to the external trigger  jack inside a door on the side of the camera.
 

Slave flash using an old speedflash head
No box yet

Developing the outdoor box design and layout. The camera needs to be able to be removed easily due to the memory card is inside a door on the bottom.