https://www.backyardchickens.com/products/ayam-cemani-chicken scroll down to bottom of page and see who has that breed.
https://www.backyardchickens.com/t/1015266/ayam-cemani-hatching-eggs-egg-sale
These 2 links may be some help to you. The second one is an old classified but the person keeps ayam cemanis. You can PM them and ask when some may be available.
There are no huge breeding facilities for this breed. Only select private breeders choose this breed.
I am personally looking for (one) hen, but they are quite pricey and they want to sell me straight run. I cant keep roosters. I also just want one within reasonable travel distance.
WISHING YOU BEST..