Talking between an Arduino BT and LED/buzzer

Hello! I need some help communicating between an Arduino BT and a LED+buzzer several feet away.

I am using 2 accels and 2 gyros to measure inner knee angle in patients with knee injury. When they walk, I want a LED + buzzer to go off when they have a 'BAD' knee angle. Using an if statement, I can set a digital I/O pin to high. I need that to tell the first transceiver to tell the second to light an LED + buzzer.

I need advice on method and hardware (what transceiver to buy).

Thanks so much,
Blue