I'm a pretty conservative dresser by nature. Not a lot of flash or "bling" in my outfits.

I'd go for a V-Neck jumper with a tie. You could probably get away with a waist coat if it coordinated with the kilt and didn't look like you were just walking around without your jacket on. As far as a sporran goes, I'd opt for the black or brown daywear sporran.

Steer clear of the wooly-pullys with the shoulder eppaulettes as this will give you the appearance of trying to look military and that would look cheesey in this setting. Casual civilian dress is the way to go in this situation.