As best I can determine, only the Head Style made its way into the game for players to use. There are several different variations on OMAC that exist in the game as NPCs, but none look like that one. The Biomech Style Set has a Hand Style and Shoulder Style that remind one of the ones seen in this concept art, but they aren't identical at all. The game's 7 years old, and we only JUST got the "Exobyte Origin" Style Set seen being worn by a hero in one of the pre-launch trailer videos. So I'm sure there's other things that were designed years ago, but which haven't made their way into the game yet.