Building a device

I am building a device and I need help developing its electronic/electrical circuit. I need the electronic circuit designed in a way to control the functions of its main components, which are all connected to one digital controller. I also need a list of all electronic and electrical components needed to make this work. The main components connected to the controller are: 1st component: A nickel-chrome-stainless steel heating element 220V 1500 watts to convert electrical energy to heat. The digital controller should be able to control the temperature/heat of the heating element by increasing it or decreasing it 2nd component: 8 12volt motors. The digital controller should be able to control the RPM by increasing it or decreasing it. 3rd component: a small 1/2” control valve to control the flow of gas. The digital controller should be able to control flow passage to let either small, medium or high amounts of gas to pass through. The flow passage should never be fully closed. I believe this needs an actuator to control the valve electrically. 4th component: a weight / Force sensor that activates all the above components if 50kg or more is applied to it based on the settings adjusted in the controller for the above components. the above components can be also activated using the start /stop button on the digital controller. I need: 1- an electrical circuit diagram. This will show me what electrical components I need to make the device work (transformers, motor, batteries, resistors...etc) 2- an electronic circuit diagram. This will show me what electronic components needed to control the device