Extremely hard to find... there's an article here that tells more about them. The only person I know on here who might know where any can be located would be ChinaChicks1
They are pretty difficult to find in North America and require special care.
If you are interested in a similar breed that is easier to find, try the Phoenix. They are a little taller, but still have the dragging tail and wing angle of the おひき. Phoenix are a little feisty and flighty by nature unless you REALLY take the time to get them used to you and to being handled.