Custom Front-end design of Wordpress plugin (FPD)

Firstly english is not my mother language. I have a custom shirt website (check this out on [login to view URL]) which is similiar with teespring, etc, and i using a live editor called "Fancy Product Designer" (Just Google it). Now the problem is, the fancy product designer is not friendly, especially for my customer. It's so laggy and lack of navigation (Indonesian people cannot understand it well, which make them leave as soon as they reach the editor page). Now i want to change the display of the plugin, but the problem is i already make a plugin for custom the Fancy Product Designer function, so now that plugin is displayed on 2 term, for customer which was displayed on Page, while the another one is for designer (to add product) which is displayed on lightbox. Now, what i needed is just fully change the display of customer version, so it become much friendly and make my customer love it so much so they won't feel wasting time using that. So the job is, a need to hire a programmer that can custom/ make a plugin that can override the design of customer editor without change the designer editor (so i can change the designer version with it's own design), as well as make the design too (both mobile and desktop). I already try to use another plugin, but it's just to complex and fancy product designer just the one who really fit my business model. If you had other solution, just let me know. Below i already uploaded the capture of my editor(access it on [login to view URL]) and the example of mobile editor design i looking for ([login to view URL]) while the desktop version is similiar to teespring version. You need to know that you can design it with your own idea, as well as it's match my theme and user friendly i won't matter. The freelancer i select in this job will get another project from me, for sure. Thank you