Diana
Why not try this suggestion I received fifteen years ago: Stand at the top of the stairs (or in the dining area of the house) and shout out each possible combination at the top of your lungs. The one that sounds the best to the future child's parents when combined is the way to go (especially since it's going to be the way the child will hear it most often after s/he learns to walk).
Phyllis
PS It'll be the way the neighbors hear it most often, too.