The Seca 899 should be your floor scale of choice: the lightest and cheapest model available for weighing children.
Electronic stand-on scale featuring BMI function.
Seca 635 large platform scale with BMI and cable remote display.
Seca 861 robust floor scale with automatic tap-on function and large LC-display.
Seca 884 electronic scale with remote display on cable and BMI function.
Seca 888 electronic personal scale with automatic switch-off.