No problemo 
Yeah, I'd suggest using a Servo, the precision will be just as good, if not better, and also they're very easy to control in software with the Arduino.
The 2nd link shows you how to move the Servo from 0 - 180 degrees. Pretty simple, just write servo.write(180) to set to the 180 degree mark. 
I haven't used encoders personally, but there's a few tutorials out on how to use them. Just give Google a search for something like "arduino motor encoder" or something similar.