Hm, I wrote up this post last night, but turns out I didn't hit the post button.
I honestly don't know how I'd do a Capt America movie.
I'd have both costumes in the film. He'd have the classic 616 costume during the WWII portion....but once we transition to present day he'd sport the UU look.
It would be
The Ultimates without the rest of
The Ultimates.
SERIOUSLY.
Granted, a lot of things would have to be altered for the purposes of dramatic depth and to fill in some of the running time.
But basically:
Scrawny kid wants to join war. Scrawny kid joins Super-Soldier. America can't replicate the formula after Professor Reinstein is killed. But they make do with what they have. One Super-Soldier is STILL an advantage.
Then, Captain America is a media sensation on cereal boxes and radio serials and stuff. He becomes engaged to his high school sweetheart Gail. He's that guy who's gonna beat the Nazis and give Hitler a punch in the face. He's going to END the war all by himself.
The first act is basically hyping him up.
But what happens is that aliens are helping these Nazis under the leadership of Kleiser, so Cap's first mission is to go there and knock out some Flash Gordon tech. And he succeeds but gets frozen in ice. No more Cap. America fights the War without Cap. History proceeds as we know it.
But then a film-maker shooting a documentary out in the oceans finds Cap's body. It's the story of a lifetime, and he gets in touch with the government and they bring him back. So they bring him back, and the government tries to use Cap as a way to increase morale and confidence in American patriotism.
It doesn't work. Because no one cares about some guy who only existed in black and white newsreels, but never did anything. He was supposed to save the world, but he never did, so he IS a faerie tale myth, regardless of the fact that he actually exists. He's the hero tale that never came to be.
I haven't figured out how the third act finishes, but basically the aliens come back. Their first re-appearance should be second act finisher material where Captain America finds himself in an isolated area --- perhaps a heavily fortified building of some kind --- and he uses his leadership to get the small number of guards to kick them in their slimy behinds.
It's a big media event, like I dunno, the aliens are holding the President hostage or some important dignitary or tourists visiting Alcatraz and although a lot of casualties ensue, Cap defeats the odds... perhaps with only a few security guards at his side.
So somewhere from there, we get a third act in which the aliens stage a major invasion for some reason or another and then Cap uses his awesome inspiringness and great tactics to beat the aliens and then blah blah fight Kleiser, A does not stand for France etc etc etc.
Basically Cap wakes up to become
Braveheart. By that I mean, a single figure inspiring ordinary warriors to send a superior force running. Only he doesn't die in the end. All this is meant to play against the fact that Cap finally becomes the hero he never got to be in the 40s.
That's my rough pitch.