Ideas for adding new birds to existing flock

[mixedflockmomma]

I currently have a Orpington rooster, 4 hens of unknown breed, BR hen, RIR hen, and 2 Orpington/BR hens. All hens are currently laying. However, my 4 unknown hens are soon to be retired from laying duty. My remaining hens are laying daily, even though its cold at night and they don't have a light. I am just not sure if I wanna add more BR and/or RIR hens, or another breed. Does anyone have suggestions on what kind of hens I should get? I would prefer ones who will lay year-round, not flighty, and are good setters & moms.