He tells Britain's Q magazine, "The film script is done. It's gonna blow people's minds, man. I'm just waiting to find out when we choose the actors.
"I want Johnny Depp to play Derek Taylor. It's got Johnny Depp written all over it, man."
And Gallagher might just land his leading man - the singer befriended Depp during the late 1990s and the actor even played guitar on Oasis track Fade In-Out.
DiLello witnessed the demise of the Beatles as an employee at Apple Corps.
Gallagher, a huge fan of the book, will produce the film.