I agree with Spats McGee, look for one with a backing option for horsehide over cowhide. It will be a few dollars more, but worth it.
For IWB, White Hat is a very good option. Definitely going to want to take the holster apart and condition the leather (to soften it), but very happy with the J-frame one I got (one of the few companies that does one with the LaserMax weapon light). So happy that I bought one for my LCP and one for my Glock 30S with TLR-3. They usually have a discount code for savings, but if something goes wrong, they stand behind their product.
Other than that, I also have a SHTF holster. Their's came conditioned, so pretty much put the holster on and carry. I have a Crossbreed Last Ditch for my LCP (Velcros on a vest), but not really interested in their IWB holsters. They don't give me options for different gun setups I have, but I also don't like the clips with crosses on them. Sorry, but when I carry, I don't want to walk around like I'm rehearsing for Boondock Saints 3.