My previous parrot was a rose breasted cockatoo (we call them Galah's here in Australia). Unfortunately Cooper got very sick and didn't recover but I had him for 18mths and he was certainly a character.
He loved affection & attention and we bonded very quickly but he was very demanding and destructive and if he didn't get his way he would scream very very loudly!! He had a puzzle toy where he had to work out how to get wooden blocks out of the holes and would throw tantrums when he got frustraled with it..... just like a child.
Deit was very easy - he ate anything, fruit & veges, pellets, whatever we were eating. He loved foraging on the ground so I would vacumm before letting him out - we have a flock nearby that spend every afternoon in the park up the road on the ground looking for grass seeds etc.
As for a cage the bigger the better, they are the smallest of the cockatoos but like most need lots of entertainment so lots of toys = room. The biggest complaint with him would have to be noise and destruction. Also I had very limited knowledge on training so I think if you get one consult an expert if you are not sure what your doing to discourage bad behaviour.
