Ahmed if you are working long hours you will need your wife to let the new grey out,it will be unfair to keep him/her caged for long periods of time if someone is home, greys are very intelligent & sociable creatures they need to interact with their human flock it will be no good your wife observing from a distance.If you go for a baby make sure it is fully weaned & eating independently,looks bright eyed, has no poo stuck to the vent area,is active & playful.Get a health guarantee from the breeder.
Please have a read through this article...it will give you a little insight in to a parrots needs.
http://www.greyforums.net/forums/african-grey/59053-a-parrots-bill-of-rights.html