Hi mishangelika,
I'm not sure I understand your question. It looks like you want to buy baby name info to use in some sort of computer application. Is that right?
If that's it, there are many sources I can think of, but there isn't a single "best" source--it depends of the information you're looking for. (Some sources are great with definitions, others are helpful for stats, etc.)
I'm guessing you have a vision of what you want to create. Just do a few searches online for books or websites with the specific info you need, then approach the author/creator to strike a deal.