All I use for my kids arrows are 5/16 dowells bought from any store that has craft supplies. The big Wmart has them.I have used several woor types and just culled out the bad ones.You can cut your own self nocks in them too. I recommend using a flu flu type feather,with bright colors. That makes easier to find and the kids love them. Plus you do not have as much invested if they do break them or lose them.
Good luck
T.J.