When I was at USAKilts and we didn't have the material, or the customer had a family tartan on-hand, we would GLADLY make the kilts. It was as simple as deducting the material cost from the final product.

I can't think of ONE kiltmaker that I know that wouldn't do that! I just finished a couple kilts from supplied tartan. I don't charge anything (since I can't) so the task is done as a labor of love for the craft. You can't make hundreds of kilts and just stop!

Pick the style of kilt that you REALLY want, and do the homework. If I were in YOUR shoes, I might even PM Barb to see if she's available! (HINT, HINT)