As the journalist, Whitaker is likely to have the most interaction with Johnny's character. A solid choice, these guys should make a good pair.
Whitaker also worked with Jim Jarmusch once, a movie called "Ghost Dog", which incidentally is the only other Jarmusch movie to feature an appearance by the Nobody character. He's been transported to a different time and place, but hasn't forgotten his catch phrase (stupid white man!).
"I feel I am good sitting on a beach with a breeze going by, the waves hitting the beach."
"I've got a lot of Barbies in storage..."
"The Mad Hatter is the Mad Hatter. What am I going to do, play him like Lee Majors?"