Who would you cast for an English remake?

I would obviously cast Ian Hart (Hours and Times, Backbeat) as the guy impersonating John Lennon. Ian Hart might want to send himself up as he has played John on stage and in films. To play an actor who is unaware of John Lennon (wasnt he in the Rolling Stones?) would be a change of pace for him, uniquely type cast as a Fab.
Bill Bailey as the acid casualty, the difficulty would be finding an actress who is convincing as a middle aged housewife and Janis Joplin impersonator.