I kept a CAG for a few years but have only babysat a zon so cannot compare.
Two of my older Eclectus really like my 8 year old grandson. They are gentle with him and like to visit with him. I didn't know this about either of them when I acquired them as they were rescues whose history was pretty much unknown to me. Eclectus are not known to bond strongly. In other words, they will drop a mate for another and will fool around with more than one (polyandrous) at the same time. This was one reason we bought our first Eclectus -- hoping for a bird who would enjoy multiple family members and friends. They do.
He is not particularly interested in my birds but these two have definitely won him over and now he understands a bit better why I love parrots. He's pretty active so they can be wary of him, but when he sits still and gently holds one for a few minutes, they both enjoy it. He knows not to stick a finger in a cage of course.
I'm not saying you should get an Eclectus. What I'm saying is, if you find an older bird whose nature is gentle and who already enjoys spending time with various people, that might be a good fit for your family and allow your son to enjoy the bird too.