Many years ago me and my father built custom incubators. The smallest was about the size of a medium microwave, and the largest was about the size of a frig. I can point you in the right direction if you need any help. Electrical is my specialty, I designed, and installed all the electrical systems. Keeping it as simple as possible with full function is the best advice I can give. Depending on the size you can set up the electrical system cheap.