This is one thing that bothers me with this particular acronym. An Autopian "PC" refers to a specific model tool made by Porter Cable, but is often used in more general term, sort of like Xerox machine. Even though it's just one tool it's called Porter Cable - the company which makes hundreds of various tools.
Anyway, for polishing there is only one (real) PC the 7424 (and its Lowe's twin 7336). Dig up the Ultimate PC Buying Guide in the Hall of Fame.