Now, here is my question: WHERE can I buy NON-GMO meat-bird chicks, which means the parents must be fed non-gmo feeds.
MontanaGal
It's unlikely that you will find Cornish cross chicks from parents that were raised on non-GMO or organic feed. The commercial breeder flocks just aren't managed that way as chicks headed to organic production are considered organic as long as they are managed as organic from the second day of life. (This stipulation allows the birds to live on the "non-organic" yolk sac for the first day of life). It's also unlikely that you'd find the breeder stock outside of a commercial setting.
It would be possible to find chicks from standard dual-purpose parents that are managed organically, but you'd have to do some searching and buy them from an organic smallholder. You aren't going to get them from any hatchery that I know of.