I think you've got the Pekins right. Also, in most cases you can sex ducks by the voice. Hens will have a definite loud "quack" while drakes sound like they have a sore throat. Unless, of course, you end up with a mutant drake like mine - sex feathers, drake color, and hen "quack".
I just didn't know if the 'quack sexing' worked with all breeds of ducks. There's only one good quacker out of 5 ducks...that's not a lot of egg production!