Well, I like leather holsters and taken care of they should last a lifetime which is probably longer than most people will keep or carry a particular firearm. I just picked those two styles of holsters because they are comfortable for me. The Summer Special was originally designed by Bruce Nelson as an Apendix carry holster but would work just as well worn somewhere around the 3 o'clock position.
I use a Looper Slimline when I carry my J-frame IWB (appendix). It is thin and lightweight, perfect for the J-frame IMO. It is also about as inexpensive as you can go for a leather holster.