I believe you can cross a RIR with a orphington. If you want the layer of a RIR, go RIR rooster over Orph hen and the pullets will be majority RIR blood and the cockerels will be majority Orph.
Do a few batchs, cull what you don't think is breeding stock (eat it), and get to where you get best...
They are a bit smaller but I have seen RIR get as big as an orphinton however, ex gf had one and she was HUGE. I have some red stars now however they're just about to be a year old and they're pretty big but shorter then regular RIR, so I mean they're great meat birds just not as big as them...