many diferent ways to go

many ways would work here
a sin city (very cartoon like cg backgrounds black white film )

cartoony (like said in previous comments like a scanner darkly (which wasa terrible movie but had a good style))

film noir (just ore regular black and white like)

gritty (like film noir but not as...black and white)
but no matter what...two face has to look like he did in the dark knight...cause that was perfect, it was exactly like two face should look

Great Story.

I really enjoyed the Bruce Timm piece.
Overall I think it perfectly draws on Harvey's most salient characteristics.
Placing Harvey as the narrator really strengthens the sisters.
I do find some melancholic comedy in the type A personality Marylyn that
would identity Two Face as susceptible to Madeline. I do feel that certain
plot points here weaken Harvey instead of strengthening him through comedy.
(IE. 'I lied...' in lieu of 'So she lied. So had I. I lied...' leading to Harvey emerging from a Reststop or Lavatory rather than staring into a lake.) Similarly, in the next plot point of, 'I tried to fight it, but I could feel my perfectly ordered world unraveling...' I lose the power of Harvey's choice to work the night after shopping with his newly wed. I think Harvey is more than just THE tragic figure. He is the TRAGIC crusader. 'Then... Alone that night, working, I couldn't finish. I wouldn't leave the office. I was scared of what could frighten my own Marylyn. I was scared to forgive...'

Apologies for the long winded comment, but I really enjoyed the comic.

How is it that the Bat would miss Madeline's clumsy acts of wanton aggression?
'Good 'ole Bruce' isn't much of a confidant but he's a great friend.

Strong graphic animation

What I really feel is missing, and could be achieved, is a strong graphic animation style with possibly live action as the basis of movements - like in Sin City & Spirit, but maybe more "live" and "rough".

Scanner Darkly

Unfortunately Timo influenced my ideas already. But the style and means in Scanner Darkly (2006) movie (http://www.imdb.com/title/tt0405296/) could be used here. Without knowing the story line the concept sounds like it could use stronger colors and contrast to support the duality.

Bizarre world

Looking at the femme fatale picture made me think of graphics artist Serge Clerc and after some digging I found again also Ever Meulen and Joost Swarte. They all have this nice graphical and bizarre style of drawing.

But because the one of themes in the movie is insanity the world could reflect also the state of mind. Especially these two images by Ever MeuIen I scanned gives some insight what the insanity of the movie world could be. The coloring is ofcourse something which should support this imagery.