Welcome to Renderosity. I hope you enjoy your stay. I'm the big, bad dragon you've been warned about. Some people around here are of the opinion that I know where everything is. Don't listen to them. I only know where 50% of the stuff is. 67%, tops.

For free, excellent period clothing, visit Serge Marck's PoserFashion. I don't think he has anything 12th-century, but it's worth a look.

If you want the transmap for the long, conforming curls, as hauksdottir suggested, here's a link:
Allerleirauh's transcurls

Yes, there are Star Wars characters, clothes, and props for Poser. Not many of the aliens have been done yet, aside from Darth Maul, Yoda, Aurra Sing, a Jawa, a couple of Jar-Jars, and a Tusken Raider. Available human characters include Darth Vader, Princess Leia, Luke Skywalker, little Anakin (Episode 1), Mara Jade, various Stormtroopers, and Qui-Gon Jinn. Lots of droids from the original trilogy: R2-D2, R5-D4, C-3PO, IG-88, etc. One prolific artist in particular has produced over two dozen lightsabers since Episode 2 was released.

The following links will lead you to most of these items. Some are found here in Renderosity's Free Stuff; the others are at other sites:

The Red Skull's Dungeon : hasdrubal's Tusken Raider
Posergamers : Mara Jade, Anakin, C-3PO, all by Jon Malis
3D Poser.com : Numerous characters (look in the Sci-Fi section)
Free Stuff : Bespin Leia and Hoth Leia, by Dal
Free Stuff : Slave-garb Leia, by Kevin
Free Stuff : ElectricAardvark's version of Aurra Sing
Free Stuff : _dodger's lightsaber collection