If you're in the USA and planning to get these birds from a commercial hatchery, don't count on those Barred Rocks being docile to other chickens. I've had some from a few different hatcheries and they are all absolute tyrants to other chickens. I'd get something full size and with a fair bit of attitude with them. Rhode Island Reds (production reds) or Wyandottes would be good choices, they're both pretty scrappy.