
I am of the oppinion that choosing ONE race and sex is good enough. I expect to come to your book to get a mental thumbnail for associating with the clothes' names. It is ultimately up to me if I want to try a particular set or piece on my toon, knowing what THE CLOTHES look like in a generic template.
If after trying a specific piece of cloth I consider it looks appealing, or somehow noteworthy, I would come and inform you about that! this makes only important additions worked on, improving the quality of the guide, although sacrificing detail.
The problems with including ALL the possibilities is the titatic work required to build the guide and the epic length it will have as a result. This means it will most probably be discouraging for both the artists and the readers! that is dangerous!