Help needed - Organizing a LEGO show on a small scale

My son put forward an idea at school council meeting to have a LEGO show to raise funds and wondered if anyone had any experience in organizing such a thing. Although I am locally known as the LEGO nerd, I know nothing really.

I guess a few sellers won't be hard to contact but who do I approach regards to people showing proper MOC's. If its not something that can work on a small scale I will tell them to forget it.

Any help appreciated.