I'm searching for a solution that would allow user to add 2 separately configurable items at once to cart from product page (separate prescription for each eye), and admin to set for each configuration a separate SKU and stock. Here's an example from VisionDirect
It's quite narrow niche to find plugin with that exact functionality. I've found THIS extension but it doesn't allow to set stock for each configuration and customers could buy lenses that are not in stock.
Do you have any idea of using other plugin and remaking it slightly or some general step-by-step for developing an extension that would allow me to add that functionality? And if that second - which existing Magento functionalities would be useful for completing such a task?
I just have basic knowledge of extending Magento therefore no idea what solution would be best and where to start if I'd decide to build the plugin on my own.
Any help would be really appreciated.