backstage communications

Hi, I haven't posted here before, but I'm with a local community theatre group in the Whitsundays.

I've been given the job of finding new headset/communications equipment for the stage crew (can you tell I'm not really a tech person?)

Currently we have fm radio transmitters (apparently from Tandy a few years ago?) with headsets, but the only thing we can find around here now are the mobile phone handsfree type things, which aren't much good to us.

Does anyone know of any companies who do those sorts of things, or could give me a better idea of what I might be looking for and where to start with them?

Any help greatfully recieved.

Cheers
Corinne