TowerPro MG90S offers a maximum of ~1.84 kg/cm torque at 5V; the alternative option Savox SH-0255MG offers ~3.4 kg/cm torque at 5V. However, Savox is significantly more expensive. TowerPro MG92B has nearly identical dimensions as MG90S/SH-0255MG, it offers 3.1 kg/cm @5V, is significantly cheaper than Savox and does not have a wide spread proliferation of clones.

Servo arm included allows you to trimmed down the servo included four-shoulder/ cross arm making print easier, and avoid stripping teeth portion of the arm. I have also included the ThumperBlock's variant of servo arm.