Hi, my understanding is that musa basjoo cannot be propagated from seed (at least the ones in cultivation), and that's why you are unable to find seeds.

Bummer! I have about six hands of basjoo fruit now waiting to harvest the seeds.Cut a couple of the fruit open this past weekend to look and no seeds! I feel pretty confident mine are Basjoos b/c they go strong from fall to spring and hardly miss a beat with the cold temps.However Bassjoo is not cultivated, are they ? Cultivated for the fiber ?

If you have not already found them, try the Seedman in Mississippi. Keyword search and it should go straight to his website. I have purchased banana seeds from him that produced. I ordered and had them the same week.