Which Focus Point Would You Choose?

My two boys are fortunate to have a pile of toys they love to play with.  Their creative energy is astounding.  I try photographing their play in new and creative ways to document their childhood, and to help me improve my techniques. 

My philosophical approach to photography is that anything can make a nice picture.  You just have to "see" it right. Sometimes I am confronted with a photograph that I see in my head, but I'm not always sure if it will work the way I want.

When I saw this picture I knew how I wanted to make it, but I was torn between two different focus points.  Should I have focussed on the airplane, or did I do it right by focussing on his hand?

Either way, I love the juxtaposition between the blue and yellow within this narrow frame.  The bright colors of the airplane draw your eye to it, whereas the hand is used to grab and play with the plane bringing me back to my original question. Which focus point would you choose?