Turns out he had the mold for a G30, so I think we're GTG.
It will be an IWB tuckable from PJ Holster, for the G39. www.pjholster.com
I've been making-do with a couple of older OWB holsters from my BIL who is retired law enforcement, until I decided if I was comfortable carrying.
I also ordered a Raven Concealment for the G37, and I'll try both OWB and IWB with it. Wait time is a little extreme at 4-5 months...
Lots of good reviews for both of these makers, it will be interesting to see how they work, or don't, for me.