Don't know how I forgot to add my comments about Poncho!
First of all - Congratulations! I've always loved amazons - my boss has one that lives in our bird room at work - he's in his 20s, and was wild caught - she's his second owner. He only says "Hello", and makes some baby noises - but boy can he sing ! He sings opera, and he's so much fun to listen to.
Now, I've read in a few different places, that an Amazon that sings - won't talk much, and vice versa. Don't know how true that is, but it seems to be true of Bubbles (my bosses bird).
I've read that if their diet isn't right, they can suffer from a Vitamin A deficiency (is that spelled right?), and that can cause liver problems. That's the only potential problem I remember reading about. Some signs of it are excessively watery droppings, deformed or overgrown beak, and overly dry feet.
Boy, he ought to be a lot of fun for you - hopefully he'll settle in nicely .... I'm so jealous ! I'd love to have an Amazon !