I'll have to say, for the QC, here's what you will need, minimally:
-Frame (can build yourself)
-Motors(4) (Brushed/brushless. brushless if prefered because brushes wear out quickly at that RPM)
-Battery
-ESCs(4) (one for your motor)
-Control system (Arduino, with gyro)
-Propellers(4) (Depends on size of frame and weight)
-BEC (5V for Control System)
-And, don't forget those blinkies
-You put those together and you have a UFO when flying at night!