Robert Downey Jr., the summer’s revelation with the huge success of “Iron Man,” is in negotiations to star in DreamWorks/Universal’s “Cowboys & Aliens,” which promises to be an ingenious mix between two antithetic genres.

Downey’s starring role in the Marvel Studios critically acclaimed box office success “Iron Man,” as the playboy billionaire who has an epiphany and becomes a hero, has propelled him to the stratosphere of Hollywood’s actors, so it is only fit that his next project should be just as idiosyncratic.

The actor is in negotiations to star in “Cowboys & Aliens,” a project based on a graphic novel written by Fred Van Lente and Andrew Foley, from an original idea by Rosenberg, according to the Hollywood Reporter.

The story is set in 1800s America, when aliens land right in the middle of a shoot-out between Apache Indians and Western settlers near Silver City, Arizona. One of these is a former Union Army gunslinger named Zeke Jackson (Downey).

The Hollywood Reporter explains that the story draws an ironic parallel between the Americans’ imperialist drive to use advanced technology to conquer the “savage” Indians and the aliens’ own attempt to rule over humans.

This is the first time the project has taken such a clear shape, as it has been in development for almost a decade, in various studios. Numerous writers have tried to come up with a script, including David Hayter (“X2: X-Men United”), Thomas Dean Donnelly and Joshua Oppenheimer (“Sahara”), Jeffrey Boam (“Indiana Jones and the Last Crusade”) and Steve Oedekerk (“Evan Almighty”).

It was only Hawk Ostby and Mark Fergus’s recent effort at penning a draft that gave the project fuel to move forward. Otsby and Fergus have previously worked on “Iron Man” and “Children of Men.”

The film could be released in 2010 but no opening date has been clearly set yet.

Downey next appears in the Ben Stiller-directed comedy “Tropic Thunder,” in August, alongside Stiller, Jack Black and Steve Coogan. In November, he appears in the drama “The Soloist.” Both are distributed by DreamWorks.