My family started breeding Large birds when i was around 7. We started out with amazons, then with cockatoos, then finally we had maccaws. From my experience, like its stated before, large birds require lots of attention and they LOVE to chew. They are a lifetime pet, and then some. Large birds have the life expectency of anywhere between 50-70 years, and sometimes longer! We mostly had breeders, but the pets we did have were put on a tight schedule. If they are used to being out of their cage all day and being handled at a certain time they are going to expect it to happen everyday, and if it doesnt they are going to throw a huge fit.
Not only are they expensive, the cage and the food can be pricey also. Just like with any animal there are certain things birds can't eat or drink. No soda ( they cant burp) or avocado. Some things are only for once in a while. Maccaws and amazons have a hard time with fatty foods, like sunflower seeds and peanuts (unsalted only.) But other then that they will eat whatevers made for dinner. But dont spoil them! lol
It's rare to see an amazon or maccaw like more then one person, they usually pick one person to be "friendly" with. Kind of like a dog has a master. They are known as a "one person bird" unlike most cockatoos which can be more of a "family bird." Not all cockatoos, but i would recommend an Umbrella. They are sweethearts.
You just have to remember that they are wild at heart and i've never had a pet bird that didnt have a bad day and just bite me at some point. They sense fear and they never forget abuse. If you can find someone that breeds maccaws, i would try and get a handfed baby, and possibly get one that is still being handfed once or twice a day. To them thats like a mommy and thats how the attachment starts.

if you have any other questions you can always email me, amyn26@gmail.com And i hope this info helped.