The ANH and ESB posters look a little iffy ... I mean, they look good, but I dunno if they quite fit the tone of the films.
But that ROTJ one looks frickin' awesome! Great work there!
I'd suggest to keep working on them, because the concept is great. Using a combination of photos and paintings, however, doesn't quite work. I don't know what else to suggest, but I'm sure with a little tweaking they can look great.