I looked at the H&R Topper single-shot shotgun but didn't like the hammer and the lack of a conventional safety. I paid $90 more to get a Mossberg 500 Bantam pump gun. It's a lot like the Remington 870, but in several ways better. It's much cheaper than the 870, it's got a tang saftey so it works well for right and left handed shooters. It has good fit and finish. The wood is kind of ugly, but it's no worse than the 870's wood. The wood is practical in that it has pressed checkering and a so-called "easy-reach" foreend that is good for people with short arms. It has a thick recoil pad. It has a good bead up front and a little brass bead in the middle of the barrel for training barrel alignment. It's got sling studs already included-- I don't know if they're quick-detach yet, but if they are, then this will be handy for the kid because he can carry the gun to the hunting ground with the sling, then remove the sling and put it in the daypack during hunting.
It's 20 gauge, comes with three screw-in choke tubes, and is set up with a dowel plug that limits the gun to single shots iniitially. I immediately trimmed it to 9" as indicated in the manual to permit two in the magazine and one in the chamber. It's got a gold-plated trigger that breaks cleanly.
Overall it's a pretty nice looking gun that seems to work well. It's American made. It's got some plastic parts, like the safety on the tang and about the trigger guard, but it's not the el-cheapo Tupperware variety and looks like it will hold up pretty well. The total out-the-door cost was $250, which was about $150 less than the Remington youth 870.
I like it. It's a heck of a good deal. Check it out if you're in the market for a youth gun.