Unfortunately the dress pictured does not fulfill criteria a) or b), but it would blimmin well fulfill c) and then some :)
However, it only comes in black or cream, is far too short, and is £95. So my plan is to try and make a lookey-likey (but with a back and a bit longer). It's basically a boat necked shift with some bits on the shoulders and a peplummy thing........can it really be that hard? Hmmmm. Why do I get the feeling this isn't going to be easy?