Inquiry about Custom Wearable Voice Recorder

I am looking for a supplier to manufacture customized wearable voice recorders. The device needs a round design (28 to 32 mm diameter, 10 to 12 mm thick), with two microphones and a small speaker. It should have one front button—short press to record, press and hold for live audio streaming—along with white and amber LEDs and vibration feedback. Magnetic mounting and magnetic charging are required. Recordings must be stored on the device and transferred to our own iOS/Android app over Bluetooth Low Energy. The firmware must work exclusively with our app, so the supplier must be able to share their Bluetooth protocol or SDK. We are flexible and can start from an existing model if it is close to our specifications, or even use an open‑source design as a base to reduce cost. Please provide: engineering costs, unit prices at 100, 500 and 2,000 units, minimum order quantity, sample availability (2–3 units first), and lead times for samples and production. A low‑cost solution is very important for our startup. Thank you.