If you're going to wear boots, I'm with McMurdo. Black polo, Ireland tartan kilt. With the boots, ditch the bright white hose in favor of some darker wool boot socks, and you'll be set.

Be prepared, as you might very well be the most casual dressed lad there, but that isn't a bad thing. People tend to overdress with the kilt. So, you'll be casual, so you'll have an excuse to act casual!

Enjoy the event, take pics, and post them!