Joomla EZauto Extension Modification

Hi skilled joomla programmers, I am proficient in Joomla Extensions installations and configuration but I need help with programming. My client's website was done in Joomla and I want to integrate this extension: [login to view URL] into his website but for displaying medical equipment. send demos of any complex extension you have modified. Be, responsible, accurate and honest as I have to buy the extension myself priced at $150. Custom programming should not affect loading time of my website. Payment will release after complete installation and testing of extensions. bugs free. Note, if you have a different approach to accomplish this with a custom component, I am also open to suggestions but EZauto is preferred. Thanks.