The misfire in that one cylinder could be any number of things. Have you tried swapping coils to see if it follows the coil? Likewise it could also be a bad head gasket or bad lower intake manifold gasket.
As for the overheating, it sounds like you got it taken care of but as these cars age, more and more overheating issues are a result of clogged fins on the AC condenser and radiator. It would do you well to remove the radiator and run water through the back side of it. Likewise with the AC condenser...
