I have a very simple remote control project I would like to put together and would like to know the best hardware to use. I want to control a single relay remotely from a distance of up to 300'. The only out of the ordinary requirement is that if communication is lost from the transmitter to the receiver, I need the relay to shut off. I only need a single input on the transmitter to signal the receiver to turn on the relay. I would also like to know if such a transmitter is available with low power requirements as it will be battery operated and I would also like to keep it relatively small.
I have just begun with Arduino's and do not know if I would even need one on either the transmitter or receiver end or if the right radio would already have inputs and outputs built in.
Any suggestions or ideas would be greatly appreciated.