didnt you make this thread before?
the only place to get them is dissidence and theyre expensive. youd be better off getting a new pro model, but whatever floats your boat...
the best you could get is a cane creek s-3 for 30. no point in spending more than that. heres the link.
http://www.jensonusa.com/store/product/HS507A01-Cane+Creek+S-3+Headset.aspx
if you want something cheaper try to get a cane creek or an FSA.