Welcome to BYC. Glad you decided to our flock. I've raised dozens of breeds over the past 50 years and I concur that RIRs are sometimes aggressive (especially the roosters). If you're going to have a mixed flock, I would suggest starting with breeds than have a well deserved reputation for being calm and gentle (potential lap pets) such as Australorps, Orpingtons, Brahmas, Cochins, Sussex, and Faverolles. If egg production is a priority, Australorps are the best layer on this list, and Cochins are the poorest layers (although they are the best brooders and mothers). Please feel free to ask any questions you may have. We are here to help in any way we can. Whatever breeds you decide to get, good luck with your flock.