In order to build your own robots, you are going to need a brain for them. The Husarion CORE2 may be just what you need. It interfaces with motors, servos, encoders, and sensors to allow fast prototyping of robotic projects.
CORE2 has DC motor ports to connect up to 4 motors. It can also interface with a wide variety of sensors. An on-board DC/DC converter is available to select voltage level for each servo.