Letting him off easy or not won't matter in five years, will it? I would say just go with Plan A, as long as the terms (not how you got to where you are) are acceptable. Try to separate the "facts" from the "emotion". There's no need to put yourself through a longer ordeal, and pay the lawyers more money, just to get back at him.
He is always going to tell himself a story about how things happened, and it probably isn't going to be very closely related to the truth. There's nothing you can do about that, so it's not worth worrying about.
As far as suffering the consequences of his actions, I think he will. You might not see it, you might never know, but if you can hold your head up, that's the important thing.
