If you need a full 360 degrees of motion you will have to be very careful with your choice of servo. Most of them only have about 180 deg of travel. Sail Winch servos can rotate through about 3 full revolutions. I don't know if anyone makes specific 360 deg servos. A continuous rotation servo would not be suitable as it has no position control.
If you can get a suitable servo it would be the simplest to work with both mechanically and from a programming point of view.
A stepper motor would be my next choice as you can count its steps and easily return to any specific position. But, as well as the motor, you need a stepper motor driver. Have a look at the links below for more background info.
If you use an ordinary DC motor you will also need a motor driver (a continuous rotation servo is a DC motor and motor driver combined) and you will need a rotary encoder to identify the position of your antenna. From a programming point of view this will be the most complex.