If they made Ayn Rand's The Fountainhead a movie who would cast?

In my opinion, the original King Vidor 1949 black and white version with Gary Cooper, Raymond Mey and Patricia Neal cannot be bettered. Of course that was 60 years ago and there is a temptation to want to see more "modern" versions of clic films with more current stars. If it were remade, I would like to see Ralph Fiennes as Howard Roark.