The web site that Casey provided concerning the Breton/Brittany Tartan sells wooden shoes (sabot de bois), the traditional footwear of Brittany, which could be worn with a Breton tartan kilt -- and a pair of Dutch wooden shoes could be worn with the Dutch Mackay Tartan, I suppose. I do remember seeing a photo of a chap in a book wearing wooden shoes for his mother's Belgian heritage with his kilt.

http://www.tartanbreton.com/

Cheers,

T.