The best way to get your Blue Orps. is to hatch them then sell what you don't want once you've figured out which is which (roo or hen). Like speckledhen says, those of us who have the blue girls usually hand onto them for dear life!
I have two Australorps, an Ancona and a Black Star. For steady laying, the Black Star is the best. She's sort of a snot, though. I love her, but she has an attitude.
The Australorps are sweet and fat and squishy, and they have a reputation for being the best layers. One of them started laying 19 weeks and is a regular layer. Her sister is the same age now (27 weeks) and still no eggs. I think she is probably an anomaly, though.