Light brahmas and white marans sound great. They'll look good next to your Speckeled Sussex. BEWARE the d'Uccle cockerel. Male d'Uccles have a terrible reputation for aggression toward people. Most don't worry because they're so small and can't cause much damage, but consider the possibility. If she has a friendly rooster, maybe he passed his good temperament to his offspring. Hard to believe something so cute can be so mean. Just a friendly warning.