lamb suede is velvet-y, and the cow suede is hairer and rougher. Stylistically I think the materials match their respective styles best. Personally though, not really a fan of black suede. It's not bad but I'd sooner get black leather and then a colored suede, like dark whiskey or the diesel blue I'm about to release (you've seen it before though, as I pointed it out in lamb suede version in a pic)
When you say match their respective styles, you mean calf suede - BCDR, lamb suede - ?