Only wing bone I have is from EZ. Great price, easy to play and still fancy enough to be a collector's piece. Tony is a great guy and easy to work with. Mine won't ever go any where, it is made out of bones from a bird I killed.
Honestly the best way to learn is to get the call and practice. Savduck has a video on you tube that has the best explanation for how to draw air into the call that I have seen. His video shows a trumpet but the mechanics are the same for the wing bone.