I don't have any experience with the ones listed. I bought my wife (she's 4'11") a 20 ga. Beretta A303 Youth Model a long time ago. My son, who is 14, recently decided that it is now his... He has used it shooting skeet and likes it a lot.

It's definitely a good choice going with a 20 gauge. A lot of people start their kids out with a .410. The kids can't hit much with it and get discouraged.