They come in all the same size classes the Malaysians do: Class A, B, C, and Micro. They just don't have the weird posture. There are Serama threads on here about them.
I have never kept them with quail. I wouldn't think it was a very good idea, but sometimes things work out. I would absolutely not recommend throwing them together in hopes that the Seramas kill off the quail as suggested by someone who has literally no idea what they are talking about...