I'm building a robot for my major work at school and need to select servo motors for the legs. The robot will have 4 legs and each leg will have 3 joints so 12 servos are needed. My robot will be similar to this robot but mine will be slightly heavier and I want to have the most torque possible under $100 for all 12 so $8.33 per servo (a little over is ok). I will also be using an arduino uno to control to robot and I want to have a servo shield if possible too.
This following webpage has a list of servos, their torque specs, and their street prices (This list is for servos made by the same company as the servos in the Instructable you referenced): http://www.servodatabase.com/servos/towerpro
For example, you can choose the SG-5010 with a stall torque of 8.0 kg*cm.
That website also lets you compare/tabulate specs of various other brands of servos, so you can make a decision that way.