Here is another educational kit with everything your kids need to build 12 models. The Fischertechnik BT Smart Beginner kit has over 380 pieces. You can program it from your tablet using an app. You get sensors, actuators, and other parts you need to get started.
The BT Smart Controller comes with 4 inputs for sensors and 2 outputs for motors and LEDs. The ROBO Pro Light software lets users program their models fast.