been trying for 5 years

I have 3 kids from 2 separate relationships. My oldest 2 boys are from my ex husband. They are 10 and 11 years old. My daughter is from another man I was with after I divorced. My current husband and I have been married for 6 years and we have had 2 children together (both boys). All together, we have 5 kids. My husband wanted to adopt my kids a year after we got married. We went to a paralegal and got things started, but we were paying her "as we went" and we ran out of money. Unfortunately, we had to drop it then because we couldn't afford to persue it. We went to see an attorney for a free consultation, and she told us that she wanted $4000 just to start. We don't have that kind of money. I bought the book "How to adopt your step child in California" and my husband and I have read it time and time again, but it is so confusing and filled with "legal speak" that we have never even attempted to try it ourselves. In the divorce from my ex husband, I was granted full custody and child support, and he was given supervised visitation rights. The supervision was required because he had threatened to kidnap my oldest son in the past in front of witnesses. He has paid child support sporadically over the past 8 years, but hasn't paid a dime since the early part of 1999. The last time he came to see the boys was in August of 1997. He hasn't tried to contact them since. My daughter's bio-dad has never paid child support at all. He was ordered to, but just hasn't. The last time he saw her was when I took her to the jail he was incarcerated in, and she was 3 months old. She is now almost 7 years old. I am aware that he is currently incarcerated. I think he would consent to the adoption. We are considering doing the adoptions one at a time beause of the cost. We want to use our tax return money to start my daughter's this year because I think hers will be the easiest. We know where her "dad" is, and we know that he really doesn't have any interest in being involved. My ex husband, on the other hand, will contest. We don't know where he is, either. Does anybody have any advice for us? Will it be cheaper to do it one at a time? It's been 4 years or more since we saw that attorney who wanted $4000 to start. Anything anyone could say wouldbe helpful. Thanks in advance. ~Erin