If you're using P8 or above, look for a poser8 directory in your textures folder. Under P8 hair there are the Allyson hair textures that look good and the Anime hair textures that are the same thing without the baked in highlights.

If your hair textures are oriented up and down, try one of these in the diffuse node, leaving the transparency map alone. If the textures are oriented side to side, you can switch the UV setting to VU.

These textures work quite well more times than you would figure.

Hope this helps.