You can use KO EX-10, Futaba 3PK transmitters.
Just purchase the KO module for Mini-z (AM 'Red color', AD 'Green color' or 2.4Ghz 'Black color'), if use Futaba you need to add a adaptor.
Transmitter around $1xxx
Module around $300-700 (AM is cheapest , 2.4Ghz is dearest)