Oklahoma adoption questions...

:flowergift: My husband and I are the proud parents of a two year old little girl, and are wanting to provide her with a brother or sister. We have been seriously considering adopting our next (and final) child. We have very limited finances, so that is definitely a concern. We have even considered fostering a child and then adopting them. We would prefer an adoption where the birthparents do not know who/where we are to avoid any complications. We are in our early 30s and are both steadily employed. I guess I wanted to first introduce myself, my name is Melissa and we live in Oklahoma. I suppose that should have gone towards the beginning rather than the middle! :) Anyway, what I am trying to find out is the least expensive (yet still safe) way to go about adopting a child. We would prefer to adopt a toddler/preschooler or a baby, but a toddler/preschooler would be best for our family. Would DHS be the best route (considering we couldn't afford thousands of dollars for the adoption)? Would fostering and then adopting be the best? What are the risks in each? Has anyone successfully adopted through DHS (specifically Oklahoma, but any state would work). What is the process like and how long does it take? Any info, including links to informative websites, would be very much appreciated! :) Thank you so much for your time! I look forward to getting to know all of you!