X-Ring also has in stock some custom Kydex IWB and OWB holsters. You may find that an M&P Shield OWB holster is still in stock. If you don't find the model holster for your firearm ask the staff for a business card or request that they place an order for you.
Things to consider when purchasing your holster:
Where are you going to carry - appendix, 3 o'clock on the hip, 4 o'clock behind the hip
What type of holster - Inside the Waistband, Outside the Waistband
What cant do you prefer at each draw position. The holster should allow you to achieve a good firing grip on the firearm as you draw from the holster.
What belt will you wear with the holster. The holster should be held secure by a properly sized belt loop so that the holster doesn't partially slide up on the draw stroke.