Where can I buy an infrared switch?

Does anyone know where I can buy an infrared controlled switch? here's my problem....My home theater power amplifier (Theta Dreadnaught) does not have a remote control. Its power is controlled by a 5 volt momentary pulse that takes it from standby to power on (or off). A 5 volt momentary pulse to a different connector toggles it between 2 channels on and 5 channels on.

So, what I want is a IR receiver that will receive an infrared command and momentarily close a switch to a 5 volt circuit. A second IR command sent to the controller will momentarily close a different circuit that will send a 5 volt pulse to the other connector, switching the power amplifier between 2 channel and 5 channel modes.

Where can I buy this or find plans to build one?