You will need to get true Ameraucanas from a good breeder. The Ameraucana club has a list of breeders as well as photos of what the various varieties should look like as chicks and as adults. www.ameraucana.org is the website. I set another batch of blue/ black Ameraucana eggs for an order, due to hatch 4/27. I always set extras so I know I will have enough hatch for the order. Let me know if you are interested. They won't be sexed chicks, though. Straight run. The black sex-linked birds are brown egg layers. Those are usually a cross between a red male, like a Rhode Island Red or New Hampshire and a barred female, like a Barred Rock. There are other ways they can be made, but that is the most common. I have some hatching that are a cross between Black Copper Marans and Barred Rock.
How many of those chicks do you think you'll have available? I may be interested in purchasing a few.