Do I need to replace air handler and compressor?

I have a Trane heat pump which is seven years old. I have been told the coil is leaking and it is irreparable therefore the airhandler will have to be replaced. Is this true? It also uses R22 freon and the industry is phasing this type of freon out. Do I need to replace the compressor also? If so, at the same time the air handler is installed?