You can't have a Captain America movie without the Red Skull. You just can't. Even the crappy '91 movie realized that (though they kinda forgot the part where he was German.....). It would be like starting the Superman franchise without Lex Luthor - just a bad idea. In regards to the costume, a tweaked version of his 'Ultimate' costume could work, or maybe they could just go with the retro soldier outfit he had in the first issue of Ultimates.