I think I would simplify the whole operation and lead halyards aft and add single line reefing with slightly oversized blocks to reduce friction. It isn't that expensive to do these couple of up grades, and the mainsail on a
Catalina 22 isn't large enough to present any real problems.
I think self tailing winches are over kill. Unless your flying a 180% Genny you should even need a winch handle.