1. I personally kind of like the retro feel of the costume shown in the original post. Maybe tweak it a bit, but the general idea I like.
2. Everyone always seem so concerned with factors like "more lead female representation in movies" and fail to notice other problems. For instance, wonder woman is getting a movie (great) but look who they cast? Some delicate pretty girl waif (Gal Gadot) that doesn't do justice to the wonder woman persona in the slightest. She's not intimidating and doesn't project "wonder woman" strength at all. She's beautiful, that I won't deny ever, but common...get over this thing with casting the most beautiful woman possible over someone far more fit for the particular role. Wonder woman should be a pillar of power and strength, strong looking, almost Amazon. The casting was horrible, yet all many people on the internet want to focus on is how women are getting more lead roles, bravo. Looking at this Supergirl....I don't know. Is that really the actress that will play Supergirl? Don't misunderstand me, I love pretty girls as much as the next guy, but too many of these women look like they'd cry over a broken nail. Can't they scout a physical looking female athlete or something like that instead? A woman with a little bit more of a physical presence on camera?
For different reasons, too many men are cast for the wrong reasons in comic movies/television too imo. I won't get into it here though.