I don’t have any available, but have had a good amount of figured claro walnut and eastern black walnut in the past- different density and heartwood color. The eastern walnut tends to be really dark in hue and the claro walnut is medium in hue. The claro tends be the popular choice in luthier building- Taylor Guitars is one of the companies that promotes Claro walnut in both acoustic and electric guitars. There is also Bastogne walnut which is also gorgeous in figured form. I probably would stay away from any crotch, feather crotch and wild grain. Quarter sawn, vertical grain would be ideal for your application without knots and burls. On a side note, I think it would be a great tandem is you use a burl walnut for your headstock as an overlay. IMHO. Good luck.