I know there's the Cricket and I think Henry makes youth .22's. Ruger also has the compact 10/22 which is easily upgradeable to any number of variations. With stocks being so obtainable and inexpensive for it, that's a very good option to go with.
I didn't start using scopes until I was an adult, but eye relief seems like the problem, as they others mention. The Mrs. can't use any of the scoped rifles I have because she's just a tad too small.
Your boy will grow into your .22 pretty soon, but Ithink the Henry Lever Youth and the Ruger 10/22 Carbine are pretty nice little starter pieces. For some people it might be better to picklever or bolt actions over the semi-autosand reinforce concentration and patience in firing. On the other hand, I'm sure you'll teach him to shoot straight from the beginning, and those 10/22s are a lot of fun to plink with whether you're seven or 77.