This guy had listed some not too long ago. I have been looking for a couple mags for my 229 but in 40. This guy has some mags in 9mm for ya tho!! Hope it helps.
http://www.theoutdoorstrader.com/threads/302941-FS-FT-Sig-226-228-229-holsters-and-Sig-228-229-mags?highlight=Sig+mag