Head over to SteyrArms - 17 round mags at reasonable prices. I have a AJConcealco leather IWB/OWB convertable. BladeTech makes wonderful OWB, concealable. Crossbreed has them... Check the Holsters vendors in the sticky thread on this site.
I went with a Remora No-clip IWB holster (size: 6-ART) and it's a great fit. Note if you order the holster to tell Alan at Remora that you need some extra space for the S9-A1 barrel. These holsters are a great value at a reasonable price and incredibly easy to carry. You can find the Remora Holster website at: