Servomotors to use with PLCs?

What does the motor have to do? It's hard to tell you what kind of servomotor you need with out at least that information. Servomotors are just motors. Motors which are controlled with closed-loop feedback magically become servomotors.

I agree without the information what you want to do with the servo or tach you have almost infinate possibilities that won't work , When you have decided what you want the servo to actually do a place you might contact is Avatron Servo (or Tach) and check out what they have . Good Luck on your redesign!