I worked with them for a half dozen years, but the babies got me out of the species. My honest 2 cents is July to September or so is when you want to shop. And don't buy any under 10 grams. Mine usually hatched at 7 or 8, and if they were eating, they were little growing machines. Fact was, some would not eat mice without being tricked. It is my belief that those should not be bred, and we would have hardier captive gray bands. But I'm retired from that fight, and mess with other species now. I dug up an old pic, though:
(This was two pinks, one's butt looked like another head)
There are a lot of good GBK breeders, consult the BOI. They are beautiful serpents, the young ones with fresh batteries are breath-taking!