I imagine that you went through a grieving process when your hubby did not want children years ago. A part of grieving is closure. Is that door really closed for you, or did you leave it open a crack in the hopes that he would come around one day? Is his openness to adoption something that he would have come to despite your daughter's prodding?
You received a lot of foster care suggestions. Please do not sign up for this without considering how the process works for kids in foster care. They have already experienced many transitions and heartbreaks... if someone comes to your home, you guys aren't prepared... don't like him or her... who knows?!?... that child will be removed and sent to ANOTHER home. The more these children get moved around, the more they suffer now and in the long run. It's terrible. Please go into foster care only after you are ready to accept the long-term responsibility of parenting a hurt child. Think of your home as the last stop that child needs to make before either returning to his or her parent or staying with your family for the rest of his life.
I'm disturbed by your hubby's logic here. Actually, I'm bordering on being offended, but I won't let myself go there until I know more about the situation. I'd love to ask him if he thinks that children who were adopted somehow require less love and effort than his daughter... like it's such an easy decision now compared to having another child years ago??? Based on what you shared, he has NO IDEA what challenges can come to your family by adopting a child. For this reason alone, I recommend a stern NO from you right now. In time you will find out if he is serious about taking on the challenges of expanding the family through adoption.
Please do not look at adoption and foster care as "saving" a child because you have the means. Because you can't. No one can love the loss out of these children. But people who are committed to parenting a hurt child can give that child a better chance than s/he may have had otherwise. Many people congratulated us for doing such a great thing, what an admirable thing, we're saving a child from whatever..... It nauseates me because these statements, however well intended, wreak of negative stereotypes of children placed through adoption. My child is not indebted to me for our choice to adopt him. I could go on... message me if you want some more of my perspective on this topic. In the meantime, you can visit www.informedadoptions.com or pick up Real Parents, Real Children by Van Gulden and Bartels-Rabb.