Once the case is filed, the court has his SSO. Unless he is going to work for a rather small company that IRS doesn't even have a record or he'll never come back to the state (which is impossible), the child support and your maintenance will be directly deducted from his payroll by the company he works for (you'll have to work with your attorney on this).
Don't make any private agreement with him, the law will not provide you any support upon private agreement.
Last not the least, the attorney fee will be deducted from his salary too if the attorney you are to talk to is really good.
Good luck