Whenever I hear Moyen, I think oversized miniature poodle. Try calling reputable breeders of minis and tell them you want an oversized one. They pop up fairly regularly. The corollary to this is calling standard breeders and asking about smaller sized dogs.
The second thing I think is Karbit Poodles. I've heard of them, but I haven't done any research. It is a place to start when looking for "moyen" size. You know, right, that we have three sizes of poodles in the US?: toy, mini, and standard. Anytime you go looking for a poodle with a different size designator than those you are heading into murky waters...
Personally I think the easiest thing to do is search out an oversized mini from a great breeder. Good luck!