The Losi radio would work, but you wouldn't be able to shift it into reverse because the Losi radio is only 2-channel. You need a 3-channel radio. Something like the Airtronics MX3-FHSS or the Futaba 3PM or Spektrum DX3S/R.
The radio comes with a receiver, so you replace the receiver in your Slayer with the new receiver, bind it, and then set up all the adjustments on the radio to work with your car.
The Slayer doesnt have reverse, so it would not be a big deal, what do you mean by binding the receiver?