Don't get me wrong, I didn't mind the design for the Sardaukar in the recent Dune film (Or as I like to call them, NASA Vikings), but it wasn't how I imagined their uniforms to look based on the, admittedly, vague description in the book. The Dune Appendix mentions a fusion at one point, long before the novels take place, of Sunni Islam and Zen Buddhism; to my mind, as far people in service to the Emperor, I envisaged something that combined elements of Imperial Japan and the Ottoman empire shortly before the Caliphate collapsed, since the Fremen in Dune are somewhat analogous to the Arab revolt of 1916