Home A/C

[gasdad]

Need some info about my home A/C so I can make a more informed decision. My central a/c unit is 19 years old. The evaporator coil main pan has developed a leak and now water is being emptied into the emergency catch pan which has an overflow pipe to the outside of my house. A/C people are recommending a change of the evap. coil which 'm ok with but should I just replace just the coil or should I just get a new a/c unit. I'm leery to just do the coil and a year or two down the line the compressor could go out and then I'm stuck with a replaced coil and compressor that will then not be as energy efficient if I were to just get a new one now. Thanks for any advice.
Sorry no fishing report