So you would like to build expressive robots? The Creature Head open animatronics kit is worth a look. It has 2 DOF eyes and jaw that opens and closes. You get laser cut and 3D printed parts, servos, NodeMCU, breakout board, Wii controller, and other parts to get started.
You can customize the parameters and make different heads to try these on. Costs $150 at this time.