If everything is as you say with the owners of the area being for us playing on there then count us in. We would love to see something official in writing saying that we have permission to play there though.
Can you post a link to where it is exactly on google maps?
We can help with any area but sounds like registration and game judging would be the big ones. We'll talk more but if it really is a go then we can make a section on the NIA site and start to give out specific jobs and form a sort of committee that would be dedicated to helping with the event. We have a few ex military guys that are fantastic at making long running and milsim (not just lots of games) scenarios.
I work for a kids camp so I am busy for the summer but when were you thinking of running this?