While I get what you're saying, WoW's graphic engine, unfortunately, isn't really designed with that as a possibility.As for the Reaper form pic I linked, there's a better view of the reaper form here: https://www.youtube.com/watch?v=n2Uc-zmiS8o from about 1:02 to 1:16 and it seems to also be his chest bones, and not a chestplate, but blizzard could make a similar design in an actual chestplate, where the center of it is plate, and then draped over the sides is a cloak, that extends into a kilt/robe that is also open over the front of the legs, so that the legplates under it are viewable as well. It might be a bit complicated for wow's graphics engine, but it would look cool at least.
Those are cool, but they look more along the lines of traditional DK armor, just with a black coloration. However, I think DKs could indeed use more of that, as most sets now are broken down into "blue, green, red" for the three specs. (It's been that way since Cata) That's kind of neat, but... it's sort of gotten old.Other sets I'd like to see for DK's are the Dark Knight sets drawn by this guy: http://reaper78.deviantart.com/
Version 1: http://reaper78.deviantart.com/art/T...11969570&qo=17
Version 1.2: http://reaper78.deviantart.com/art/M...11969570&qo=16
Version 2: http://reaper78.deviantart.com/art/D...F11969570&qo=5