The PC is black tie equivalent. If there are going to be lots of PCs at the event then there should be lots of black bow ties.

If it were me, I would wear the winged collar shirt and a hand tied black bow tie. I would be willing to bet that most of the PCs will be wearing pre-tied, elasticated bow ties. If you don't know how you have nine months to learn how to tie a bow tie. At the event, your hand tied will always trump a pre-tied.

Regards

Chas