Inquiry about Voice-Controlled Calculator OEM/ODM

I am looking for an OEM/ODM manufacturing partner to develop a standalone voice-controlled calculator. The product should support voice recognition for spoken calculations, with a built-in microphone and speaker. It needs an LCD or OLED display, a rechargeable USB-C battery, and offline voice processing capability. The design should be compact and handheld. I need a partner who can handle product design, prototyping, and mass production. Please provide details on minimum order quantity, estimated prototype and mass production costs, and production timeline. I also require custom branding with my own logo and name on both the product and packaging. Please share your previous experience with similar electronic or AI-enabled products if available.