Why not get rid of the option alltogether and chose whatever parts you want on your toon from the 'body' menu during char creation? Of course that would need some rewriting and remodelling as stuff clips like hell already and even more so if all clothing options would be avaidible in all costume slot types... (there are…
The male/female switch to me is more about the visible features of a character anyways. Andorians (AFAIK) have 4 sexes, and need all of them for unassisted procreation... etc. Why not get rid of the gender/sex option alltogether and chose whatever parts you want on your toon from the 'body' menu during char creation…