If you are willing - and able - to provide a child with a loving and stable home, and you, as a couple that is unable to conceive (or who wants to expand your family but can’t) can have a child, then it doesn’t matter how that’s achieved!
When it comes to domestic adoption, the benefits are that you are likely to adopt a child who is still an infant, and where you have access to medical and other records. However, there are strict laws regarding the process, and the birth mother or parents will have the option of changing their mind.
Foster care is a much less costly process, however, the child you foster is likely to be older, and may have been exposed to traumatic experiences that may affect behaviour.
International adoptions are predictable, in that you can expect to receive a child within a definite timeframe (after you’ve been deemed eligible to adopt) however, there are likely to be little or no records for the child, and your adopted child may have a different cultural or ethnic background to you.
Whichever you do choose, remember that giving any child a good home is a great thing, and if you can be of benefit to a child and expand your family, you’re all winning!