WTB wireless mic set

[panfry]

I am looking for a good reliable wireless mic set. I help announce at a local BMX track and need to be able to roam around. I would like a head worn set with a body pack. I need to be able to go about 50 to 75 feet from the receiver. This track is a non profet organization and we do not have a lot of money to buy a new one. Any help would be great.

Thanks
Russ