Hi guys!

My question i want to get help on may yet be directly related to arduino??..... Sorry...

I am building my own cnc router useing arduino uno and shield and i would like to know from you guys who have some experience with cnc builds, If i go looking for a er11 spindle dc spindle motor  "What am i looking to find out how much power it has"????? I can guess it would be "Watts"?
And, if i would like to engrave regular mild steel, What "Wattage"? am i looking for?