I would agree that making six tartan kilts for different people in different tartans for a wedding seems a bit of a nightmare to me-and actually more expensive than going with one of the economy kiltmakers. If you really want to do it, I find that as far as prices I've seen, House of Tartan's mediumwieght polyviscose is great kilting material and much less expensive than wool. It's $21.70 a yard right now.(as compared to $62 for their cheapest pure wool) You can find them at http://houseoftartan.co.uk/

Hope this helps