Where to put stronger servos on humanoid?

I have servos (17  of them ), making the Sainsmart 17 DOF robot, and I have 2 more very strong servos.
I am wondering which joints will need stronger servos, ankles, hips?

servos on humanoid

Mount the servo motors on the bottom of the piece of plastic near the front. They should be sideways so that the shaft/horn (the part of the servo that moves) face the sides. Make sure there is enough room to mount the wheels.

There is no plastic on my

There is no plastic on my robot.

What wheels?