Mat poses could be a way to go. These are basically pose files that change the relevant parts of a status. Before the introduction of material files (somewhere Poser 6 or 7?) mat poses were the way to apply materials. Problem is they easily mess up your material setting.

Another route is to have your material refer to all colors and styles and use dials to select the ones you want to use. Problem then is Poser loads 8 files but it uses only two of them. Note latest version of Poser13 has better support for keyed inputs.

How did you make the colors and transparency maps? If you used one base couple and made other colors via filters in Photoshop, you could probably achieve same effect by pulling the textures through a HSV node.  Same if your transparency map for short style is a scaled version of the long style, playing with the uScale or vScale of the image node would save you a map and give you any style  between long and short.

Last but not least you may consider letting the shader refer to maps on a fixed address and add some Python code that copies the relevant files there. In this solution the choices will survive save and reload only if the copied files are not changed. Also you can only have one color-style of your hair in a scene.

None of these solutions is ideal,  but hey such is life.