Are you looking for hatching eggs or chicks? Have you looked in the appropriate section here on byc, or the breed associations? I don't remember many buff Ameraucana breeders here, but there are tons of Marans folks.
Hey there!
I know the perfect place...Eight Acres Farm. You can look up cpartist, the owner's byc name (real name: Luanne) She's been very professional with me so far, and I'm sure she could help you find someone if she doesn't have what you need. She's in North-Central Florida - so the only downside is that you'd have to pay $45.00 in Express shipping to get chicks to New York in a day. Includes chick box, heat pack, & Gro-gel. Eight Acres breeds to the APA standard, and from the looks of it, they know what they're doing. Only catch is, she's got Wheaten Ameraucanas, not Buff... very similar in the hens, but slightly darker hackles. Her Marans are Blue, Black, and Splash Copper. They're pretty typey, considering the difficulties in breeding Marans for egg color and conformation @ the same time. Good lines too. I would encourage you to see the other breeds on the site while you're at it... hard to find some of them.