Thundrr-Chicken gave the reference I was going to. If you really look at it, you will see that you get pretty much the same service from the major hatcheries. Different ones offer different packages and may have different minimum amounts, but the success and problems all average out. They are not going to stay in business if they don't offer good service. With hatcheries hatching 100,000 chicks a week, you will sometimes experience mix-ups, but usually not. In my opinion, the best hatchery to order from is the one that requires less shipping to get to you so the chicks are in the mail a shorter time period. If you live close enough you can go pick them up direct from the hatchery, that is even better.
Vent sexing chickens is not easy. The hatcheries normally offer a guarantee that you will get 90% accuracy, and this is only on large fowl chickens. They don't even try bantams. The actual success rate depends on how good the professional doing it is. If you order commercial red sex links, you should get a real high success rate (like 100%) unless they totally mix up the breeds. I have not dealt with black sex links so I don't know how much judgment is actually called for in determining if they have a white spot on the head or not.
They arrive in a box in the mail. The box is delivered to the post office and the post office gives you a call to come pick them up. The box should be marked with your name, address, and phone number with instructions for them to call you when it arrives. It is a pretty good idea to talk to the post office people a day or two before you expect them so you can discuss how the procedure works there. The shipment usually comes in very early, before the post office is open for business. Some will call you before they open for business and let you pick them up at a back door while others, like mine, will not call before they are open for business.
