Need Help!- Servo vs Stepper?

[Eusk]

Hi, I am having some truble getting the steppers from my provider. So I coulg get some used servos, so here is my cuestions:

1. If Iwas going to use 1000 oz/inch stepper wich will be the maching servo?
???Volts and ?? A. Any servo con the proper reduction will work?

2. A servo needs a driver according to its Voltege and ampers. Are those the only parameters to take in cont at the time to choose a servo and its driver?
The driver could be from an other brand? For example simmens servo with a yaskawa driver?

Are the Geko servo drive good fr any servo? and do they close the loop? For Example with a simmens or Fanuc servo?

Thanks for your help.