Small (DAC) Digital-to-Analog Converter for iPads and iPhones

Dear all, We are a company that deals with repairing needs in major cities in the UK. The clients we deal with have trouble with their 3.5mm Jacks and would require an alternative (DAC) Digital-to-Audio Device for their Apple Products We are looking for engineer with expertise in Audio, Analog Engineering and Electrical Engineering that truly understands DAC such as knowing 16-bit to 24-bit and Sampling Rate of 96Khz to begin with. Therefore, these are the 2 requirements we need, please apply only if you are confident of achieving them: 1) Able to a make small DAC (Digital-to-Analog Device/Adapter) that has iPhone 8-Pin MFi Certified lightning connector with 3.5mm Female Jack 2) Have necessary contacts with Manufacturers who have Apple MFi Manufacturing License.