L.M.
My x husband adopted my daughter. I got permission from biological dad. He signed off. This is the easiest and least expensive. AS for child support, if he owes money, he will owe it after the adoption unless you agree to sign off on it. I used it as a negotiating tool. I signed off for the signature. You will not get child support after the adoption if you get it now. It wasn't horribly expensive $500 or so back in 1991. I would not do it without a lawyer. To many variables that could go wrong or be missed. Good luck!!!!