The point of steppers is that you don't need feedback. You tell them what to do and they do it. Probably. You need to ensure that your steppers and power supply are up to the task and that your controller software doesn't ask the steppers to do something that is beyond them.
That said, I was working on a project recently where the stepper just responds to step instructions and a rotary encoder lets the Arduino to figure out when to stop. I'm not entirely convinced that the encoder is strictly necessary, but it does help persuade yourself that the stepper is doing what it was told.
I suggest that you start with steppers alone and see how you do. Leave the encoders until you can't live without them.