Plymouth rocks are a very good breed. They are cold/heat hardy and I have not had either of my 2 Plymouth Rocks go broody since they started laying (about 1 1/2 years). They also lay quite well too.
Just be careful on the amount of chickens you get at first. Usually people (myself included) plan on only raising a few, then they become so addicted to them they can't seem to get enough. Enjoy!