For the Dune board game custom portraits project: [link]
EDIT: 7/11/2013 Major repaints on this set.
Most of these guys are in Sardaukar armor. I'll style them basically as Ottoman Space Marines.
According to the book, the Emperor Shaddam IV is supposed to look 35, and he wears a helmet with the coronet built in.
I cast a younger and heftier Salvador Dali as Emperor. (more Jodorowski Dune trivia).