I think you will be hearing a lot of crowing in the future. I think both of your blue black chicks are orpingtons and are male. I also agree that the ones you suspect on the other breeds as male are indeed male.
thanks for all your posts. I was thinking i had 4 boys. thankfully i have found homes for what ever turns out to be a boy.
Gutted about the brown orpington as they make a fab pair.
Sadly i can't keep the roos as i have neighbours.