MAKE SURE your baby is fully weaned. Do not let anyone try to sell you than line about how it will bond better with you if you are the one to hand-feed it. That is false and a lot can go wrong.
Have you tried "Strictly Feathers" in Knoxville?
What about "Adventure Birds of Bon Aqua"?
Here's an Aviary (dk much about it)
https://www.facebook.com/myaviary615/ (they get 5 stars out of 17 google reviews--but again, dk personally)
A lot of times you put a reservation down on a batch of babies that is coming up, so just because a bird place doesn't have a certain type of bird, doesn't mean they won't. The issue then is that you are committing before meeting, but if you are wanting someone to ship then you would be doing that anyone. Shipping can be really hard on them btw (not saying it can never be done, but I was unhappy with my experience flying with Noodles in cargo)..It's a lot of stress for them and the temperatures etc can get super sketchy during transport.
I also just saw this place in Kentucky-- "The Parrots Nest and Pet Supplies"
https://www.facebook.com/TheParrotNest/ <--even if you don't want to drive there yet, it is clear they have babies from time to time, so if you know what you want, they would probably let you reserve over the phone and then come get the bird when it's ready.
I also found this "Mystic Moon Aviary"
https://www.facebook.com/MysticMoonAviary/-- You always kind of have to use your judgement, but they SEEM legit at a glance anyway...
Frankly, if a person has limited supply of parrots and doesn't talk a ton about shipping etc etc, I tend to trust them a bit more, just because it seems like they are breeding on a smaller scale and probably less for major profit, but maybe that's just me...I am very weary of sites that act like they have tons of options all the time, ship wherever, etc etc (seems too good to be true, or like a bird farm in some respects).
Have you had cockatoos before? I would strongly advise against getting one without a lot of experience around larger birds, but specifically, experience with cockatoos . Also, with babies, it's easy to make mistakes that last (and it's also a bigger shock to your system when they go from a baby to an adult years later--because of personality changes etc) AND because rescues are so full of cockatoos ...
PERSONAL OPINION: I know you don't want to rescue, and this isn't a guilt trip for you, but I have a hard time trusting any breeder who is actively breeding lots of cockatoos in the US...That's my personal bias, but when they are re-homed more than any other bird, and there are not enough homes for the unwanted ones, I cannot imagine creating more of them and perpetuating that cycle as a breeder (knowing statistically that 9/10 of my babies would be bounced around for the next 60+ years) ... I know that there is a market for it, but..seems odd..I mean, if it's once in a blue-moon, I can possibly see breeding them with pre-screened adoptions set-up in advance, but if they are breeding lots of "toos" and selling them at pet stores etc, that freaks me out.
Another thing, although they are tremendously different in many ways, technically cockatiels and cockatoos can reproduce...so keep that in mind as well.
You aren't wanting to get both a conure and cockatoo at once, are you?