I don't think there's any better IWB for concealment and comfort of carry for a big gun, in this case a fat gun, than the Milt Sparks Summer Special. There's a good wait to get one, but they're not expensive. I don't know what they're going for now, but back when I got mine 10 years ago, it was fifty bucks well spent. I think I had to wait several months to get it, but it was worth the wait! I carry a Ruger P90, big gun in it, and it hides well and rides comfortably. The one gripe I had was the spring at the top, the leather that covers it, would dig into my side. I finally wound up gluing a piece of leather over that which goes up to protect my skin from the decocker, too. That really improved the comfort. I understand the holster has been redesigned now and that annoying lip around the spring has been eliminated, so apparently I wasn't the only one that had problems with it.
I've had good luck with Mitch Rosen, too, but his stuff is a little more expensive. No more functional than the Sparks stuff, but it's a work of leather art. Rosen stuff is beautiful. I mainly spent the money because I wanted a tuckable. There are other tuckables out there to choose from now days. That "Workman" set me back $140.
I've done the cheap spring clip holster thing, the Uncle Mike's cheapo thing. I think buying quality leather for IWB especially is a must. Pocket carry isn't as big a deal and OWB is comfortable with off the rack stuff, but IWB demands a quality rig IMHO.
