For efficiency you want the most egg weight in return for feed weight input. The leghorns are unbeatable. On the downside they are skinny, bony meat birds best used to flavor soup. They don't have enough meat for dual-purpose use. The other downside for egg sales is the white shell. Folks want fresh eggs to be brown shelled. They think they taste different. All eggs, white, brown, green, or other are the same inside. I raise mostly brow shell types because they sell better for direct purchase. I also raise games. They are hard to beat for foraging and production. Shells are cream color. The roosters can be a handful though. All are fun to keep.