Choose a brand: Futaba, Airtronics(Sanwa), JR or KO PRopo.
Go for a synthesized radio (no crystals). A new Futaba and a new Airtronics MX3S is on its way.
You'll fork out about $180 without the servos though. Make the investment now. Make sure that most of the trims, tuning can be done electronically (mechanical trims are out). Must have at least 10 model memory. If you're racing T-Max or Savage, make sure its at least a 3-channel radio. ABS works well for larger scales those with independent braking to all four wheels.
But, very importantly, choose a radio that feels comfortable in your hands.
Vrmmm