After looking at the new TV costume here:
This where I’d go with a Wonder Woman movie or TV costume – more Greek with a Corinthian helmet, arm guards and greaves. I haven’t coloured as my colouring is worse than my pencils. I see the armour as leather and in a russet red – the leggings in blue and greaves, arm protectors, helmet and belt in bronze. The corinthian helmet effectively works as a mask so gives some plausibility to a secret ID, I’d leave the lower face somewhat viable so the actress has a chance to express emotion.
Re plots I’d up the Cthonic elements of Greek mythology (no thats not a mispelling of Cthuhlhu http://en.wikipedia.org/wiki/Chthonic) with anti-crime or anti-terror plots. I’d also have her get full on hoplite with shield, sword etc; againist really big bads.