I highly recommend the Kydex products from Blade-Tech.com
You will want a holster that is concealable, comfortable, accessible, durable, covers the trigger guard fully, is tension adjustable and is quick. All of these requirements are satisfied by the Blade-Tech standard High rise, forward cant model.
I don't recall the model name, but you'll find it on their web sight.
Don't forget Mag pouches. For IDPA I would get a Double Mag pouch. Blade Tech has them as well.
For belts, they cary the very versatile and stable Wilderness "Instructors Belt" which is "Bullet Proof" and provides a very stable platform for mounting the Holster and Mag Pouch.
Over the past 20 or so years, I carried and competed wearing leather products from Sparks, Davis, and Galco. The advantages of the Kydex products I think are superior for all of the above listed criteria. Plus, they will last forever.
If you want the feel and warmth of leather, I would look at the products from Milt Sparks Leather, Davis leather and the Wilson Combat offerings.
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ACK
"Make the First Shot Count"!