If you don't have an old control system lying around (or just want something way simpler), 1540's had a lot of success with the AndyMark Cheap 'n' Dirty controller. It's a regular joystick controller that sends radio signals to a tiny box with 6 PWM outputs - plenty for our purposes, at least. It can be had for only $55
here.
You don't need a driver station, laptop, or any software whatsoever to drive - just the remote, a few AA batteries, and the receiver.