There's so many choices out there, it's not even funny.
If you're truly talking about investing in leather, look at any number of custom makers - Sparks, Rosen, Alessi, Del Fatti, Andrews, Bulman, and many others. You'll pay for it, and you'll wait for it, but the end result will be a work of art that'll last a lifetime.
If you want decent quality affordable leather without waiting 6 months or more, Galco, Don Hume, DeSantis, and Gould & Goodrich are some brands that stand out in my mind.
Kramer is a company I consider in between in terms of price and wait time. I have to personal experience with them, but I understand they have a pretty quick turnaround, and their prices aren't too terribly bad. I've been considering picking up a couple of Kramer belt scabbards sometime in the future.
On the gun boards, what gets recommended seems to run in waves, fads, whatever you want to call it. Some of the standards are the VM II from Milt Sparks, Comp-Tac's C-tac, and the various hybrids such as the Minotaur, Crossbreed, etc.
In terms of decent, simple, relatively inexpensive OWB designs, Galco has the Combat Master, Gould & Goodrich has a model damnear identical to the Combat Master, Don Hume has the H721OT, and DeSantis has their Speed Scabbard. Not as inexpensive, but not any better (IMO) is Galco's Concealable.
You might also check out the offerings of Fist. They're a custom maker, but I personally don't put them up there with Sparks, Alessi, etc. Then again, you also won't be paying as much or waiting as long for the product, either.
Me? I've been carrying my G19 in an Alessi CQC/S for the past few years. I just recently got a Don Hume H721OT for it, as well. I liked the design, and it was only $40. Works just as good as any other OWB, but it probably wont last a lifetime like some of the high-dollar custom makers' stuff. It's a good holster I don't mind scuffing up or otherwise abusing.
I carry the 642 in a Galco horsehide pocket holster, but only when I'm wearing some Carhartt shorts with pockets big enough for this method.
I carry my 3" GP100 and my S&W M&Ps in holsters I made myself.