You want ready to use drive hub or you can make it to fit?
If drilling or milling does not scare you, you can take this one:
http://www.ebay.com/itm/5M-HTD5M-Aluminum-Timing-Belt-Pulley-40-Teeth-14mm-Bore-16mm-width-Stepper-Motor-/261916119702?hash=item3cfb6ad296:g
hgAAOSwpDdVcTgc
that is what I got.
they come with different bore sizes too