Tapping into Ford Excursion Ignition Circuit for DVR install

Hi ya'll

I feel pretty stupid asking this. And this is kinda a strange question. We are installing a Digital Video Recorder into my 2005 Ford Excursion to record video incase of an accident for evidence purposes.

Basically, I need to know where is the correct place I should tap into the "vechicle power supply"?

and where the ignition switch sensor line is located to trigger the unit to power on or off.

Note: the unit can be programmed to power-off X ammount of minutes after the ignition is switched off.