I spent some time in the past few days to test the two leg designs that I came up with. The first one is a more "traditional" one where the two servos are placed in series just below the hip where the femur bone would be. The second one places the motors at the hip (root) of the leg, and uses a scissor mechanism to realize 2-DOF movement.

Overall I've found the second prototype to function better, providing more accurate and smoother motion, despite the fact that it's a bit harder to build.