IF you should choose to ignore the excellent advice already given and wear a ruche tie, at least try to get a self-tied one. That will allow you to modulate the "over-scrunchiness" that mars the pre-tied ones.

Also, a ruche is the wrong length to go with the short, 3 button waistcoat normally worn with a PC. A cravat looks rather better tucked into a 5 button waistcoat, which leads you to a black Argyll jacket. As far as why one wears a 3 button waistcoat with a PC and a 5 button waistcoat with an Argyll, I believe it has to do with the length of the lapels on the jacket.

The versatile Argyll and 5 button waistcoat (with the dreaded ruche or a standard four-in-hand) would probably be a better choice for an event that starts during the day and extends into the evening anyway...