I would start with lav mf cross if I have to start from scratch which is what I'm thinking. I love the color from when I had the d'uccles but I love my cochins more than the d'uccle breed so I'm going to begin the project this year.I've thought about it... A lot too.
I was thinking of a blue mille crossed on lavander or Millie crossed on lavander would work.
I