Robert,
Hello there. I have a commercial FM Radio Transmitter from BSW if I am not mistaken. It's been sitting in storage for a couple of years, unfortunately I don't remember all the specs off the top of my head right now but I do remember that it transmits in standard FM radio band Freqs of 88.1- 107.9. I don't remember if the transmit power is 1 watt or 5 watts, but the one time I toyed around with it I had about a 1 mile coverage at a race track in Arizona. I'd be happy to let you borrow the guy to see if it will work out for you, unfortunately I in New York until thursday night and don't have access to the gear until Friday. Let me know if I can help.
Oscar