Scottishkilts.net is great. Their turnaround time is absolutely outstanding. I ordered a kilt from them and had it in my hands in under 4 weeks.
A tartan would be an expensive proposition and I'm not sure that it would fly. A kilt pin, otoh, might be doable. Should stay away from the enamled stuff though. Looks too much like junk sold to tourists as momentos of every cattle crossing they pass through. Perhaps a nice cast X done in celtic knotwork.