ArcTeryx Bora 80 for the boys and ArcTeryx Altra 62 for the girls. Shop around and you can find them for under $300 occasionally.
Got to be one of the best quality backpacks out there. Have very thick padding on the hip belt and shoulder straps. I have tried some of the cheaper options out there but they just don’t seem to cut it when the going gets tough.
OSSH 