Engine Misfire

I have a 2001 Jeep Grand Cherokee V8- 78,000. A Couple of weeks ago I had a rough idle and a check engine light. Scanned to find that I had a misfire on cylinder seven. I changed plugs and moved coil pack from cylinder seven to cylinder one, reset computer and drove. Check engine light came on again and still read cylinder seven. I brought it in and had a motor vac service done to clean the injectors and still have a rough idle and check engine light for cylinder seven. I then did a compression test and am only getting around 45 to 50 PSI on cylinder seven and not holding very well. Thinking it could be a burnt or stuck valve and may bring it in to have heads removed and rebuilt. Could the misfire have damaged the piston/ring/ and or cylinder to where when I do get full compression after the head rebuild that it would blow that cylinder out, possibly from the unburnt fuel in the cylinder? What would be the best course of action now? Thanks very much :