I think the charcoal jacket will look great. I will probably get one myself when I can afford it.

I know it breaks "the rules," but I'm a big fan of wearing a tie in the same tartan as the kilt. I think the waistcoat creates enough distance between the tartans that it makes up for any differences in color, sett size, etc. I've worn a tartan tie with my kilt to a few weddings and other casual/semi-formal occasions, and no one has ever said a thing.