Acoustic guitar, archtop guitar, electric guitar, and ukulele wood sets Ukulele wood sets of Hawaiian Koa. Curly Koa Guitar Wood is one of the largest suppliers of curly Koa guitar wood for guitar building anywhere in the world. Located in Hawaii, we are able to obtain only the finest pieces of this rare exotic wood for guitar making. We have the largest luthier supply of quartersawn Hawaiian Koa for guitar soundboards, backs, and sides.