Total nightmare i'm afraid, DON'T USE CSA, i've been through it. We came to a private arrangement about money and it's worked out ok, even better now i've gone prematurely retired i pay her only half as much as i did.
BUT please factor in here, her reaction to the said split, it won't be easy. My ex was ok till she found out i'd got another girlfriend (3 mths after split) it went mental.
You never know anyone till you divorce them :|