Picking an age range or sex of children to foster

Hi all. We are taking our classes right now and then comes the 2 inches of paperwork and the homestudy. We are thinking of chosing the age range of 0-3. We have a just turned 5 year old and dont want them to be too close in age.... Our ultimate goal is a baby girl that we can someday adopt, we have two bio boys and have always wanted a baby girl. BUT we are wanting to foster as well, but not sure if we shoudl limit it to only girls or foster both. I feel bad if we only foster girls, BUT am scared we will be placed with a boy and miss the opportunity to foster a girl. I dont want to put too many limitations on our ranges because I know that will limit our placements. Sadly, my husband has declared that we cant foster african american children as he is just not comfortable with it. I on the other hand welcome any child, but as this is a big decision for both of us, I have to respect his decision, even if I dont agree with it at all. Any thoughts??? Or reccomendations??