Simpul,

Bringing own PC it's not what I will recommend. I'm afraid it will cause more problems on the day. If you have your own gaming PC u can test it before the event and that's much safer.
Letting others bring their own pc you will probably face games version problem, some might have hacks inside their PC. If one of the participants PC infected by network virus, then it's going to be a big problem.

There's lotsa gaming tournament around the globe, you can take their rules as reference just make sure their rules are up to date.