I can highly recommend Simply Rugged pancake style holsters...
Carry a 3" GP100 often in one with great results and good concealment,
Have one for a 4 5/8" .41mag Blackhawk also...carries well IWB, although it's not exactly a T-shirt and shorts rig![]()
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.
Don Hume H715M W/C IWB Holster Review - YouTube
2. For revolver holsters, I recommend looking for a holster that carries the cylinder at the same level as the belt. You can tell by looking at the belt loops in relation to the molding for the cylinder. It may seem counterintuitive to stick the thickest part of the gun in your waistband directly underneath the belt, but I've found this to be the most stable design, which helps with both comfort and concealability.
Same height & weight here!Ops summed it up well
While I prefer a 2 1/2 or 3 inch 19/66 for concealed carry I can carry a 4 inch 19/66 in a Milt Sparks Summer Special. 5'9" 165lbs... 34" wranglers
Always good to spread the JMCK word -- to which I'll add that the IWB 3 for Js and Ks is now available for quick ship.Tony at JMCK (JM Custom Kydex) makes great holsters, (I have three or four) and the IWB 3 gets rave reviews from those who carry IWB.
IWB 3 Holster: JM Custom Kydex
I carry AIWB as IWB is not as comfortable or convenient for me, but I'm sure you'll be pleased with the workmanship and quality.
Outside of leather options, it's the most popular holster for IWB I've come across in the past several years.
ETA: I see you've made your choice. Perhaps the suggestion will be helpful to another member.