My Pet Chicken gets most of their birds from Meyer's, and other local hatcheries. only a few breeds do they hatch themselves.I highly recommend My Pet Chicken. They will be fine in the mail. Be sure to look at which breeds are aggressive and those that are "friendlier." Don't mix them or their will be bullying. The stores like Tractor Supply often will give you the wrong sex and you will end up with roosters. Also, chicks grow so fast that if you don't get them at the same time, you will end up with big ones that pick on the newborns. Good luck!
Birds are individuals so you can't often blanket and say 'friendly breeds' or 'aggressive breeds'. :]