Courts generally do not accept a voluntary termination of parental rights as that would include a termination of parental responsibilities. That is unless there is someone else ready to stand in. Your best bet is to find an adoption attorney who will work with you, and have the biological father surrender his rights and consent to the adoption in one proceeding.
I wish you the best of luck,
Courts will not permit the bio-dad to get out of child support this way.
Secondly, if the plan later is a step-parent adoption, you will destroy that plan with papers now. Consents for adoption must be in exactly proper form and TIMELY.
When you are ready for the adoption and can afford it, rights can be surrendered during the adoption and your adoptoin lawyer can draft the documents then.