Questions you should answer about your stirring application:
What are you stirring?
What is the approximate viscosity of the solution?
What is the vessel size that you will be mixing in?
What speed (in rpm) is desired?
What is the torque requirement?
What is the duration of the operation?
What voltage and frequency do you require for the control (most in the U.S. will be 120V, 60Hz, while some areas overseas require 240V, 50Hz)?
Are you presently using a stirrer for the application? If so, does it work well, and what is the horsepower of the motor?
What agitator (paddle or propeller) do you want?