I think they should keep the split suit thing but not make it stupid looking like in BF. How I would do it...
Get a guy like Guy Pearce or Gary Sinise or something who looks like a genuine good guy, and have the accident where his face gets all messed up. I'd go with a bit of a greenish purple tint to it, not a purple and not a light blue or something too odd but like a mutated green/purple. Half black suit, half brown/tan/white/gray/blue, whatever. Half has to be black though. The coin, I'd definitely keep, but it would act as his conscience. It wouldn't be "I have to flip the coin until I get what I want" like in Batman Forever, it would be more like, he only uses it when he doubts himself, and when he flips it, that's the deciding factor. Say he has Batman beat to hell and his thugs want to finish him off, he'll flip the coin and if its Harvey's side, he'd go "No, leave him. Let's continue with the other plans" or something, you know?
And I think everyone loves the death idea where he throws all the coins up and it makes Harvey do something or other, that was always kind of cool.