I you investigate dynamic hair, my favorite 'free' is "Kate Hair" that comes with Poser7 (and perhaps earlier).  Just scale it up to 105% (or so) for V4 or other models. It comes with shaders for color and noise, which of course can be tweaked.

a big issue -- since you have gone for realism shaders on skin -- is shadows from hair. Nothing shouts "fake hair" more than hair that does not cast shadows on the face.

And thus, a challenge. It costs render time, a lot of render time, to make hair cast shadows properly. Especially if you seek to have STRANDS cast shadows!

But if you don't attempt it, the contrast between the high realism on the skin and unrealistic behavoir of the hair under light will always look odd.

::::: Opera :::::