Miami Fruit will reportedly ship them to you. Unless you live in California or Hawaii, much to my chagrin...

I've seen a few places sell them. It's a specialty item and I suspect you need a specialty grocer or be some place where you can grow them. (e.g. in the tropics or semi-tropical spots, you can grow a variety of banana varieties that you can't really find in stores).

They still exist, mainly on small scale farms in tropical countries. You can find them in local markets.