Some suggestions:
Servo's: JR3550 - Airtronics 94145 (both are fast and weight about .95 oz) - have seen them go for $30 used
Receiver: Novak xxl (only .5 0z) - have seen then go for around $25 used
ESC: LPR Comp2 or Novak GTX - these will be the most costly but can be found for around $90 used