The cow rawhide that 3rivers sells is apparently quite thin, but I'm gonna go with the whitetail. If nothing else, just because it's whitetail, which is what I plan on using it to hunt with at some point. Besides, that's what I originally wanted, but couldn't find it (just found the goat and the cow). So thanks for the link.
I've heard that III isn't great for rawhide backings, because it gets really dark when it dries, and doesn't look great since you can see through the hide. Can anyone confirm or deny that?