Here's another question to add.... the swivels for the sling are build into the gun but include the little oval shaped piece so how the heck do you attach a normal sling? Don't they all have that part on them when you buy them?
P.S. if you don't know, the front sling swivel also serves as the screw to hold the forend on.
I would look into a 2-7 sized scope. You could mount it low enough because of the small objective lense so the kid doesn't have to stretch to see into it and break his cheek-weld. Nikon makes a few good 2-7 scopes on the Prohunter and Prosteff lines.
You unthread the sling form the loops that come on it and thread it onto your loops that are mounted on the gun.