my silk capes just arrived and i dyed a few this morning..not sure if they are what you are looking for, but these are one size fits all, very drapey, hooded, they have long straps that tie on so they dont slip off and there is enough fabric to tuck them to hide or cover up a costume
examples at
Akai Silks
if you open the flipbook to the second page (drag the corner) you'll see the front of two of them