K.P.
My mother was adopted when she was 4, her biological sister was 5 and my grandparents were in their 40's. I'm just being very candid here and will say that healthy infants are harder to come by and tend to have "wait lists" whereas older children are less likely to be adopted over the age of 2. My grandparents knew that they did not want an infant b/c they knew that they wanted to give two children who would not otherwise have a home the chance to be part of a family. There were definitely some attachment issues with my aunt, but the love in that house was amazing! Both of my grandparents are gone now, but they worked very hard to create a strong sense of family and support.
Infants, as you know, are tough b/c of the intense care they require. Older children, however, may come to you with attachment difficulties (depending on where they are coming from). If you have the patience and ability to adopt a child, then please do so. There are so many children who do not have loving homes who have the potential to be amazing people!