I have 3 Golden Buffs now but my plan is to get 10 more next year. I am not planning to get any roos at this time. For all choices, cold hardiness is very important. These choices are coming from the Meyer Hatchery catalog descriptions and also talking to Meyer Hatchery personnel. Not to mention some posts on BYC.
My choices are:
2 Rhode Island Reds - excellent egg layers and docile
2 Speckled Sussex - very good egg layers, calm, just like their coloring/markings
2 Buckeye - good egg layers, friendly, calm & sociable plus I'm from Ohio!
2 Ameraucana - blue eggs, like the coloring, good egg production
2 Welsummer - good egg production with speckled eggs, docile/friendly, like the look
I would talk to people in your area and see what does well and then also just research the breeds and see what fits in with your lifestyle/family.