I am going to be live video streaming a sporting event. We are going to have 2 commentators announcing and I want to be able to stream their audio as well. Is there I way I can plug into their soundboard and wirelessly transmit the audio to my camera. Similar to what you would do with a lavaliere mic?
Sure, just figure out the gozintas/gozoutas of their console and your camera.
Why bother to go wireless? I'd stay hardwired just to make life simple. If you MUST be wireless, even a Sennheiser G3 can work. If they only have line out, you needs to get an adapter cable to handle that.
Get everything well in advance of the broadcast so you can play with it and make sure everything works correctly.