I guess the motor in front is a Servo, but without picture it's hard to tell. You probably also have somewhere a magic circuit to control the speed of the rear motor. If you're lucky, connecting the truck to an Arduino is very simple.
As to RC equipment, forget about making it yourself: Those are cheap commodity items and not worth re-inventing, better just buy a transmitter/receiver combo on ebay from China.
If you want to fool around with the Arduino, make it autonomous or control it via WLAN or Bluetooth if you have one of those shields.
Korman