None of the "exotic" leathers is actually used as a foundation for a holster nowadays.
(Shell cordovan, that is, horse muscle fascia, is an exception, being used full-thickness in holster manufacture. This is a very fine-grained leather which wears well, and looks quite nice. It isn't typical shoulder "horsehide", but a non-hair-bearing layer of tissue.)
Rather, the foundational leather used in making the fancy rigs is typically cowhide (steerhide, actually), with a thin layer of the exotic skin over that, bonded and/or stitched.
Alligator, crocodile, "lizard", ostrich, stingray and shark all have interesting textures and patterns.
Shark and elephant are very tough, stingray is a bit less so, while the others are rather more delicate.
Obviously, it's a personal taste issue in a CCW holster, since nobody should be seeing the rig but you, most of the time!
Of course, for a "barbecue gun" worn exposed at your next wingding, you may want a fancy setup with silver conchos, turquoise, and those fanciest of holster leathers, full-quill Ostrich Labia (apologies to Lou Alessi) or frog scrotum (apologies to Matt Del Fatti)!
I have Bull Shark and Shell Cordovan holsters and belts, and they're sturdy and serviceable. I think I've actually scratched drywall with the Shark belt by mistake a couple times. It's REALLY tough.
Best.