AC Servo Motors and Drives

Hi group, I have been playing with CNC stuff for a while and have
built a couple of systems with steppers and Dc servos utilizing
Geckos but I recently ended up with some AC Servo motors. As I
understand it they are kind of like 3 phase motors in the way they
work, 1) am I right & 2) are there any gecko / inexpensive type of
drives to run these motors using step and direction pulses?
Any direct answers or pointing in the right direction would be
greatly appreciated.

David