Where to find/buy photoshop files for skins?

[Mitch B]

Using smartgwtpro and the designer I work with is asking for a template or a master document that would have the Photoshop source files for a specific theme. He hoped that this might expedite propagating a modification throughout the theme and avoid having to edit all the images in one of the themes already provided.

I have looked around for any info on vendors as well but I was not successful, so any suggestions there would also be appreciated.