I'd give serious consideration to the Don Hume H715-M holster for an IWB holster for a Model 19. I carried that model revolver as my duty weapon for nearly a quarter-century. Mine was a 4 inch that weighed around 37 ounces empty.

You didn't mention where around your beltline you'd be carrying the gun, so I suggest a clip-on style that can be moved around as necessary.

I've used the H715-M holster for my EDC gun, an S&W 3953 semi-auto. Don Hume has been a long time police holster supplier so it's not surprising they have this holster for the S&W K-frame models, i.e., Model 19 in a variety of barrel lengths.

I've found these holsters wear well, are comfortable, and are serviceable after several years of daily wear. I highly recommend it.

Check out the video below from a company that has the best price I've found for these holsters.