Auteur study, further decisions

After ditching the idea of studying Francis Ford Coppola, moving swiftly onto Quentin Tarrantino and then feeling like he would be to easy to do.. I am again stuck choosing between two directors. David Fincher and the Coen Brothers.
I've come up with a couple of different aspects to look in to:

The Coen Brothers
- the obscure
- use of the same actors
- botched crime, a crooked criminal - obsession with film noir
- an average joe who gets involved in a big scheme that is too much for them, something goes wrong with the plan and chaos spirals
- the effect of money on people, negative
- violence death and murder
- distinctive, american settings - malice in familiar settings
- greed and corruption

David Fincher
- a master of form, shot angles and filming techniques
- visual style, dark and gothic - flashy
- working with Brad Pitt
- Life theme, teaches a life lesson
- Downbeat endings
- Title sequences that set the tone for the film

I'm really stuck as to what to choose, I'm drawn to Fincher because he is undoubtedly an Auteur and has a brilliant visual style, but also drawn to the Coens just because it's far more light hearted! I am going to see what articles I can find on both and will probably end up doing the one I can create the best catalogue for.