I'll also chime in for the Rem. 1100 Lwt. 20 with the 23" barrel and 3/4 oz. loads. I've used a stock-shortened one of these for years with both ladies and youth instruction and they suit well... unless the kid is especially small in stature when they begin. My gun continues to function well when cleaned properly, and have had no issues there. For safety reasons, students are always handed just one shell at a time for loading, and the skeet (screw-in) choke has them hitting clays in short order.
As for the .410 being a good starting gun, no argument here as my Win. M42 with modified choke (1/2 oz. - 9's) throws some impressive patterns @ 25 yards with good density in a 26-29" spread. The more open choke in a .410 might just be the ticket for the smaller kids that would have difficulty with the slightly heavier semi-auto.
rob
