I hope you can find some young chicks! I guess though you could get one of the older chicks and try it. Sometimes it works, sometimes it doesn't. If you could pick out your bird, you could pick a smaller one or a lower on the pecking order one. That would probably grow up to be a more docile bird, and it might bond to your chick well. Of course, you'd have to wait until your chick is 4 days old or so before integrating it in with the older one. The older one would be about 2 and a half weeks old by then. So I'm not sure it would work. You would definitely want only one older one though. The majority of times I've tried this it hasn't worked. Usually the little chick gets hurt by it (whether on purpose or accidental) or gets terrified, and won't go near it at all, ever. The only time it worked for me was when my 2 week old single bob chick's siblings hatched (I had set 3 eggs before the other's, but this one's 2 siblings died prior to hatching) I put them in one at a time wit him. Now he acts as a mama to his 9 little siblings. He's a very good boy.
Like the others said, a hen would not work. She would have to go broody by at the very least today in order to accept it. And even then she might reject it. The hen will not accept a chick if she's been broody for only 5 days, for example. It has to be about 21 days.
And you still don't know for certain this chick will hatch. I hope it does, of course, but be prepared that it may not. So wait to get any companion chicks until it hatches. Make sure you have some places to get them lined up though. Good luck! I'll be watching for the update. Let us know if you find some chicks!