I've had a rescued Gray for about 8 years now. He was 10 when I got him, so he is still a juvenile.
Getting a parrot is a lifetime commitment. It is very similar to having a baby! You cannot leave them alone for long periods of time. They require a LOT of attention and care. They are not a pretty bird you can just put in a cage and feed once a day.
Grays are very prone to feather plucking as they are very intelligent birds. If they are over or under stimulated, they will pluck and once started it's very hard to stop, even if the stress that started them in the first place is fixed.
They can be very destructive....Toba Bird will get into anything and everything, and when we tell him "NO!", he will go in his cage and sulk and say "BAD bird Toba, BAD!". He's a hoot.
Not all will be talkers. ALthough they have the capability to be very big talkers, some simply never have the urge to talk. So it is not a guarantee by any means. Toba knows over 300 words, songs, whistles and sounds and learns more by the day. Others I have fostered never learn a single sound.
They require a very varied diet as well and will not thrive on seed.
They are wonderful pets, very loving, very entertaining...but a lot of work and commitment, so not for everyone. One of the biggest sins in the bird world is to get a parrot, not have the "time" for it and rehome it. NO parrots do well at rehoming. Before we got Toba, he was extremely hand tame. The trauma of being rehomed started a feather plucking stage that lasted years, and he no longer likes to be pet and touched. He is happy and healthy now, but he refuses to be picked up or pet because of the rehoming trauma. The people that had him loved him and took very good care of him, but they had a baby and he was no longer "number one". He hated that baby to the point where they had no choice to rehome him as he would hurt the baby.
Getting from a good breeder is an abolute must as well as a bad start in life will forever affect their health and temperament. Find a hand fed baby from a good breeder, or look into rescue. Rescue is challenging but very rewarding.