The Bull Dawgs Club
I've been very impressed with the quality of Talon leather holsters (Tallahassee, FL). Unfortunately they don't offer an IWB holster for the G39 specifically. But they offer (of course) one for the Glock 30 & 29 (item number GK30-IWB-T) and one for the Glock 26 & 27 (item GK26-T-IWB)...