$450 with or without the scope? If you're scoping it anyway, I'd suggest a Marlin 795. Plastic stock only, inexpensive, etc. Sights on it are poor, but if you're scoping it (like I did mine) it hardly matters. High capacity magazines can be had, but I personally don't find they add to the experience. Extra time loading=extra time not shooting, big and clunky etc. My own sensibility.

Anyhow, one of the most accurate 22 semis you can get under $500, and you could get 2 of them for that amount. Choosing one will leave extra $ for a better scope. Light enough for the kids to use. If you want to see an interesting review, go on YouTube and search for Marlin 795+Nutnfancy
If you want to spend a little more, you could get a stainless steel 795, or a Marlin 60 with a wood/laminate stock. The model 60 feeds from a tube magazine, the 795 external box mags.