Alarm system programming and hardware

I need an alarm system for a nursing home where there is a reciever in each room. When a nurse has a problem and needs help they press their own transmitter (possibly clipped to their uniform) the reciever in the room sends a signel to a main board in the nurses office to show which room that nurse is in. The signal will light up a LED light and give an audible sound.
Job is for all units to work in Australia - 240V with back-up battery.
Need price per unit for approx 40 room recievers and 10 nurse transmitters as well as the main board in the nurses office. Looking for interest - the job has not been passed by management yet and I need information and costings to take to the board.