hoping to adopt baby girl with Down Syndrome

I have always felt this special place in my heart for children with DS. My husband and I have spoken many times about adopting a baby girl with DS. We like to volunteer at the special olympics and everytime I always find myself talking to them ...or watching them and cheering their accomplishments. I always get this feeling that i am meant to be a mother of a little girl with DS. When i was in junior high I volunteered in the special ed class and was drawn to this one special girl. Later as I started babysitting i had the pleasure of babysitting 2 girls with DS. Maybe that is where i started to gain my love and respect for them. My husband grew attatched to one special boy with DS before I met him, while he was serving a mission for our church. We have always been interested in fostering or adopting a child with DS. We are foster parents who have adopted our 5 year old and our adoption for our little girl who is now 6 months will be finalized in 12 days. We want the next child we adopt to be a baby girl with Downs Syndrome that we can get from birth or at least very young. We would go through DHS but it seems that it is very rare that they ever get a child with DS.....so we don't really know where to go from here. We will probably want to adopt again within 5 years. Does anyone know who we should go through.....since we want a newborn..... international adoption won't work for us because we won't get her until after she is 6 months old. Also we have been blessed by adopting through the state so we haven't had to pay anything for our previous adoptions. How can we keep the cost down on this adoption if we aren't going through the state? What is our likelyhood of finding a newborn baby girl with DS? Our family is very excited about our growing family and is also excited that we are going to be trying to adopt a baby girl with DS. Please help with any information. Thanks Jessica