Circuit board design

Hi, I'm looking for somebody to help me with designing a circuit board for prototyping purposes. Unfortunately, I'm unsure of the technical specs, so this will require some consultation and work on your part. Looking for someone with experience in the areas of C/C+, microprocessor design, coding and working with battery powered electrical components. I'm looking for someone with excellent English skills and who is comfortable with writing code and picking the best components for use with a air/water timer powered by a 9v battery. My goal is to prototype an air or water flow timer for commercial markets and the circuit board/microprocessor must be able to process a handful of very simple steps. For example: 1.) Sensing when pressure is present when flow starts, possibly via a simple push button that is located within the air/water stream. 2.) The push button will activate a buzzer after a specific amount of time. The buzzer alerts the user that only 2 minutes of full air/water flow remains. 3.) After 8 minutes (or two minutes after the buzzer sounds), the air/water flow is reduced to approx. 25% of full flow. 4.) After the air/water flow/pressure stops (i.e. when the user switches off the air flow after use), a timer will wait three minutes before re-setting the device to allow full air flow. This will stop users from turning off device and immediately turning on again to get full flow again. Simplicity and reliability are important. I am very clear about the end result that I want but am very open to suggestions and ideas on how to get there. This design would include very simple components like a buzzer, 9v battery, air flow restrictor (solenoid, actuator, gate), microprocessor(s), spring(s), and/or magnetic latches. Ideally I am looking for someone with some experience in prototype design and circuit board coding and design, as well as someone who can think outside of the box. The initial phase of the project would include 15-20 minutes of Q&A, coding the relevant steps, proof of process, and 10-15 minutes input from freelancer about having microprocessor/circuit boards manufactured per spec. Project could continue indefinitely with additional contracts with the right person.