I have the same gun and carry it all the time. I have 2 holsters that I really like. I have the shoulder rig from Dillon Leather by Mitch Rosen. The model holster is the G17R or 36121. The thumb over is a liltle tight at first but with some oil it stretches and closes perfect and fits the gun perfect. I also have a Blackhawk CQC Size 02 Glock 17/19 Holster that slides on the belt and has an extra magazine pouch forward of the holster...it's really simple, easily concealed and retains gun very well. Another accessory you may want to look at are the Pearce Plus +1 or plus 0 magazine extensions. For my concealed carry rig i use the Pearce PG-330's with just add an ergonomic grip. For the range I use the Pearce +1 grip which give you 7 rounds. I have like 6 mags total. Good luck and check out my blog at 2ndAmendmentright.org
Thanks, W