Hello Debbie, good luck in your search. There are going to be pros and cons with every breed, and there are always chickens that don't quite fit the breed description.
I have odd colored Leghorns from a show breeder, so they will be a little different than the hatchery ones. They do OK in the heat, but last winter both of my boys ended up with frostbitten combs when it got really cold. Extra large combs are a Leghorn feature. As far as kid friendly, the girls won't hurt anybody, but they would prefer that people just let them alone. Their breeder's kids were picking up and handling the original ones that I bought, so they got used to that. My roo doesn't go along with the mean rooster stereotype. He comes up to me to "talk" and doesn't mind his feathers stroked. Leghorns are supposed to be really good with confinement, which is one reason they use them for battery chickens, but how confined do you want them to be? They need room to scratch and peck, and they will fly out of runs that don't have a top. They are excellent egg layers, but have so little meat on their bones that they're hardly worth processing. Some people still process them.