Thanks Phruby - I might sculpt the collar, but I'm not sure yet - I really try to avoid sculpting if I can - it's not my strong suit!
For the hair, what I did was use two separate types of thread, one thin, one thick (almost like shoestring).
Before the head was on the figure, I removed her "real hair" - the head is from the SAGA Padme Pilot for both figures.
Then I put the head on, and wrapped the thin thread tightly around my pinky finger about 10-15 times, then would glue it in place so each strand of thread would stay together. After it dried, I would cut off the wound thread with one snip, then I would have one solid section of "hair." I did that about 6 or 7 times and glued each one to her head.
Then I realized that I needed to build up the top of her head, so I drilled a small hole in the top of it - and stuck in a piece of a lightsaber into it to give something to build hair around.
At that point I used the thicker thread, and glued/wound it around the small piece of lightsaber sticking out. Then used the thin thread to wrap in turn around that. A touch of glue here and there, and now I need to paint the figure, and touch up the hair a bit.
I'll probably use the same method for the other sister.