I think I've found Atom's look. Or, at least the closest to what I imagine.
[hider][img]http://jessperna.com/images/caricatures/fine/superhero_caricatures/manga_superheroes_ad_t1.jpg[/img][/hider]
First of all, this was an extremely lucky find, since the design incorporates the letters M as well as A as emblems, easily representative for his name: [i][b]M[/b][/i]ighty [i][b]A[/b][/i]tom. I also like how this features a white and black color pallet. The white could his normal "Combat Mode", but then he could also be able to swap to the black one as a pseudo "Stealth Mode" for more covert operations. Finally, just imagine the helmet either being removable or it simply retracts to reveal his face, to give him a more photogenic look for public appearances and whatnot. His hair - though obviously just a cosmetic choice - would be short and blond, same as the man who inspired the design of his face, and likely kept in a strict military-regulated style.