I just looked through one of my parts drawers and found an old HPI Receiver. It's AM, ch3, orange and 27.095.
Before you order any new ones you need to make sure that you have either an AM or an FM system. One will not work with the other. They are tuned to the Tx and Rx.
Do you have a complete extendable antenna on your transmitter? How about the receiver, how long is the wire?