Tractor Supply chick days actually start as early as the 20th of this month, depending on your local store. Mine is getting them in on the 20th. You might want to call your store and see if they'll get them sooner than you think :)
Also as was mentioned, any other red sex link will be basically...
I can't speak to Rural King specifically, but if it's like ordering with other feed stores, you're actually just going through them to have them order for you from a hatchery, which will then send the chicks to you. So you're kind of just using a middle man to order from a hatchery.
Tractor...