I've been looking around since buying a Glock 22 last week for a shoulder holster to use when the weather cools off in a few months. I hit ebay and many other websites to see what was available and study how they were made, with what, how thick (if leather), and strap width of the different ones out there. I'm sure I didn't see everything made but saw a good many of them. I finally made a choice:
Gould & Goodrich GoldLine: 804 Shoulder Holster (Fit 15 RH Brown) $111.49 at OfficerStore.com
The holster has thicker straps than some other popular brands and is real leather with moulded holster at a better price.
ps; I'm not an officer of any sort but the store has good ****