I'm afraid you won't find what you look for. The Gorgons are currently a discarded concept (one of the reasons was that D&D is a modern fantasy while Heroes 1-2 feature classic mythology or fairy-tale concepts).
The exception is made towards the concepts of Might & Magic VI: The Mandate of Heaven, for this is the game which officially continues the story of Heroes 2 and its plot has a special place in the development of H3SW. Yet, we tried to make these concepts looking more H2-ish all the way. Some may still need graphic improvements.
A little priority is given to some MM3-MM5 concepts, for these were the games which were predecessors to Heroes 1, the graphics of which in turn inherited many feats from these games. Some new heroes are based on the portraits from World of Xeen, just like their older H1 brethren are.
Still, some H3 and even MMVII-MMVIII concepts may still find its place in the bestiary of the game. There are a lot of people wanting them, counting some of the team members, so probably there should be a decent compromise sometime.