Congrats on the new bird Terri

, whats his name?
I am not sure what you want to know, I know that you already got tons of bird experience.
Let's see if I can break down the differences between Stitch and Leroy, in regards to their body language. I cant promise that this is related to amazon behaviour, but they DO behave in different ways (it might be because they are just different birds, not because they are different species).
Stitch is, just as you say your new guy is, a cuddlebug. Most people who dont own amazons think that they are not cuddly birds, and sometimes that can be true. They are cuddly when they want to. I can scratch Stitch head everyday, and he always ask for some head scratches every evening before going to bed. Leroy on the other hand, a bronze winged pionus, is more reserved with cuddling, and I only get to scratch his head occasionally (and my wife isnt allowed to at all, even though he allows all other forms of handling from her). So there's definitely a difference there.
When it comes to temper, there's a world of difference as well. Stitch is more like a rollercoaster, he can be superhappy, superinterested, and he can also be very very angry. This can fade pretty quickly. Leroy is mostly just calm and a little reserved (but much less so now

).
Tell signs that Stitch is angry are:
Pinning eyes, I know that some say that it can mean that they are happy as well, but in Stitch's case its always always that he's either angry, or overly-excited (which will lead to possible aggression).
Spreading of tail feathers. This is a sure sign to stay away, and dont agitate him.
(Leroy doesnt do any of this, he always shakes his head when he is angry).
Tell signs that he is happy:
He makes kissing noices, or speaks when he is the most happy. Always talking and chattering away in the shower.
He will preform random tricks to show that he wants us to start a training season.
Sometimes he flies over and wants his head scratched.
I am probably missing a lot of signs that I see everyday, but react to unconsiously to, or that I am just forgetting right now.
Stitch is a handful sometimes, but he is oh so intelligent, and it shows. You really have to be consistent with him but he is at the same time a joy and I love him dearly. Zons really are personalities, which I am sure you will come to know if you havent already.

If there is anything else, or you got any questions, just shoot and Ill try to answer to the best of my abilities

.
Oh, and regarding amazon size, ours is a lot smaller than a BFA, but he's still packing the full amazon punch let me tell you that

!