The difficulty with trying to model individual hairs is that the polygon count gets ....errrr ..... hair raising :)

I've seen some good wigs made this way but their downside is that they weigh in at more faces than the figure. Rendering times become so long that if you did not need a hair cut at the start you certainly will at the finish. Not to say that you shouldn't try, just be aware of the pitfalls.

Good luck :)