Wireless Audio/Video setup

Hi there

I have been asked to look into wireless audio/video setup for a hall. (30m x 20m)

I need advise from the experts in this forum as to how I could achieve this (DIY style).

Also if this is achievable via wireless computer network. (Detailed explanations on this would be really appreciated).

Basically the setup must allow audio from four microphones (live audio) to a amplifier and then onto the speakers.

Video would be transmitted to other monitors in the hall.

Any advise would be really appreciated