I would disagree about Lehorns--while they lay super well, they're Mediterranean breeds and don't do well in very cold weather. They also aren't the friendliest birds. I have nine or so right now, and they are fine with weather in the 20s, but I have to watch their combs once the temps are below zero and they don't like to lay in winter without supplementary light.
If the most eggs for the fewest chickens is your goal, try any version of the red or black sex link. Red Stars, Cinnamon Queens, Golden Buffs, ISA Brown--these are all versions of sex-linked red chicken. Black sex links are often called Black Stars. These girls are bred for high egg production and will lay all winter with minimal light. They're not funky heritage breeds, but they will lay 6-7 eggs a week on average. They are egg laying machines like Leghorns, but MUCH friendlier. In fact, my Golden Buffs are the friendliest, calmest chickens in the flock.