I can cut a couple dozen rose shafts for you (if I have time, I will de-thorn too...otherwise, I will wrap them so you don't stick yourself on a thorn).  Let me know if you want more/less.  I would trade dozen for dozen.
I will cut them to 36 inches.  What diameter would work best for you?
I would prefer close to 11/32" or 23/64" in diameter.  I do not have experience with sourwood...not sure of potential spine weight after they have been seasoned.  
Thanks,
Dino
If possible, please respond to dinorocks at gmail dot com so I don't miss your response.  Thanks!