Prototype Home Monitoring Sensor Stack

I need someone to help me prototype a home monitoring sensor stack. We want to include a camera, microphone, and ideally an infrared sensor in a compact design. The project requires expertise in hardware and electronics, particularly in sensor integration and miniaturization. The ideal candidate will have experience in electrical engineering and embedded systems. I am not looking for someone to help me build it. I will first pay for consultation. I am more than capable to assemble all the parts. I need consultation on what off-the-shelf sensor stack I can use which is readily available to order and can fulfil supply of 100-200 units. I tried iterating using the Raspberry Pi Zero W 2 with an Arducam camera module but realized: 1. The Pi's are too expensive and sold out nearly everywhere 2. The camera just did not possess the image quality comparable to even the front camera of an iPhone SE. We need good a camera with great resolution. Our budget per device is ~$90.