Hello, I think the buff one might be a male not based on the tail feathers but more on the comb growth, and the other chick has a high chance of being a female.
If you end up having cockerels on your hands, my favorite method of getting rid of them is auctioning them off at my livestock auction- however, if you do not have an auction near you, I bet you can sell him on Facebook marketplace or Craigslist, or perhaps your local humane society! Or if you don't want to go through all that hassle, many peeps who end up with a roo just cull him. Not an option for many, considering people who raise their chicks as pets often end up growing attached and don't have heart to cull their cockerels.
I do suggest waiting it out a few weeks though until you know for sure. Don't want to accidentally get rid of a pullet!
