First of all, anyone advertising "Miniature" Boston Terriers is probably not a good breeder, as there is no such thing, really. Some are naturally a little smaller or bigger than breed standard, but there's no recognized "miniature" so either they are breeding in a smaller dog - a Chihuahua for example, or breeding the smallest Bostons to each other, and likely creating genetic problems breeding closely related dogs, so best stay away from them.

You can look for Boston Terriers on http://petfinder.org and I bet you can find plenty of Bostons needing homes, you just have to put in your zip code so it can show you ones near you!