Free: Contests & Raffles.
Cochins are your best best WSU for a full sized chicken to go broodie. They are also wonderful parents.
You honestly would do better unless interested in the hatching process, just buying chicks at Big R, or the co-op. Not trying to discourage you by any means, but the best success is buying an incubator. The basic of basics probably run about 30 bucks. (thats 10-15 chicks at the feed store). Then you have to deal with humidity, temp (electricity going out), turning the eggs and so forth. It really is a fun process and if you are serious, let me know and I can help you. Its a great kid project.