I've got three hens, I haven't a clue what they are and I have a cockerel. They have the run of the garden and frequently head off over the back and sometimes end up around the front. I live in a block of masionettes and have neighbours to the left, right and above and everyone loves them I do pass out surplus eggs to keep everyone happy, it's hard for someone to complain about the chickens if they are getting something from them.
If I were you I'd go for rescue hens, you are giving them a new life. Mine were rescue, not from a battery farm but from a tiny little pen where the people who had them had no idea how to feed them.
If you are going the free range option, make sure you have an outdoors cat for ratcatching (mine bring one into the house at lease once a week... ickky but at least the rat isn't eating the chicken food, the chicks or eggs)
We don't have foxes around here, plus if we did there are plenty of rabbits to eat, I've not had a problem with them yet, but the cockerel will go for anything he thinks is attacking his hens, even me. He does keep the trespassers out of our gardens.
If you do get some, please let us know how it's going