Important, if you are thinking about getting an Arduino Uno or Mega for start-/track call-/pit lights, you may want to wait about 1-2 weeks, because than we expect the Smart Sensor to be available.

The Smart Sensor is an Arduino based solution for pit in/out detection (or sector) AND it supports start-/track call-/pit lights. More details to follow soon.
If you dont need or want the sensors, than getting an Uno or Mega is still an option.