I would suggest Australorps for the fourth breed. I've raised them for years (along with dozens of other breeds, including all of those on your list), and they are extremely hardy in both cold and heat, calm and gentle (my children and granddaughter made lap pets of them), and the best layers of the standard, brown egg laying breeds. A Black Australorp holds the brown egg laying record with 364 eggs in 365 days, and while none of mine have ever reached that kind of production (and likely never will), I've still had some of them lay over 300 eggs in a year. Just a word of warning--your feed store RIRs will not meet the APA standards for RIRs and will most likely be Production Reds rather than true RIRs. And while they will be very good layers, hatchery quality RIRs (Production Reds) are sometimes aggressive.