Some things to bear in mind:
Not all the chicks may live, whether ordered or hatched. Is your son okay with that?
If you hatch yourself, there is always a chance there will be a significant birth defect. Can you handle that? How about your son.
You can read through some threads to get an idea of what I mean.
Chickens can be a great 'circle of life' teaching tool. Some kids are too tender-hearted though.
A suggestion: Find out where the shows are in your area, and go to them. See the birds, see what is for sale there. Maybe there will be some young birds your son can handle and learn to take care of. Chicks are just so very fragile and high maintenance.... Especially during the winter.
Another suggestion: Look into d'Uccles. Although very small as chicks, they are very sweet birds when they mature. The hens love attention and the small size makes them easy to handle, care for, and cheap to feed. And they are incredble eye-candy birds, too.
If you get a
Brinsea, I
my Octagon 20.....