I decided to set my Imperials apart from the standard because, as I stated before, I just can't get the White Stormtrooper look quite right, and I'm sure there will be plenty of them around for me to oggle.
My Imperials are the 4/507th Rakshasa Regiment. They are mostly Chiss "volunteers" that work under Imperial commanders in league with the Chiss Ascendancy. They are used in action on the outer rim in places where the Empire expects heavy casualties and does not want to expose too many of its own troops (not because they care about them, but to deny the Rebel Alliance any victories)
Currently deployed to Geonosis, the Rakshasas are coming the tombs to clear out any last evidence of the birthplace of the Death Star...
I still have a lot of finishing work to do on them, but this force is ready to be in-game and I can actually take most of them to my FLGS without horrid embarrasment.