Combine functionalities of 2 fully developed Joomla modules in one

I have 2 fully developed and fully functional Joomla 3 modules and want the functionality of one of these modules to be included in the other. Further details (incl. mockup and the code of the 2 modules in question) can be made available upon request. Development as per Joomla best practice, with all language strings in ini files and all CSS in style sheet. Payments will be release upon milestones achieved.