RE: Is there such thing as a super slow servo?
The speed of the servo would depend on how fast you change the control pulse width - the rating you see for a servo is the maximum travel speed for a given amount of movement.
I'm not too sure just how synchronized multiple servos would be for very precise movement. The servo position is controlled by a variable width pulse, and the pulses need to be sent continuously in order to operate the servo (just one pulse will not work). It takes several pulses to get a servo to move to the intended position.
Stepper motors and stepper motor drivers are fairly small these days, and can be moved very precisely - they are used in almost all inkjet printers for both paper movement and print head movement, so old printers are a convenient source of parts.