Wordpress woocommerce custom plugin development

General information for the website: We sell custom printed t-shirts
Kind of development: Customization of existing website
Description of requirements/features: We are selling custom printed t-shirts and we have the same base products and variations, but with different designs printed on them. We are using a plugin called "Extra product options", where we could set several global product variations and we would like to have the option to assign a .png design to each of our products, so we will have global control of our product variations while changing only the designs that are printed on our t-shirts.

On the frontend we will need 2 upload fields that are created in our woocommerce product edit page: Dark design and Light design, because we print dark designs on light garments and light on dark ones. We would like to be able to assign a link to those designs via csv product import, because we import all of our products.

As far as the variations - we would like to set the type of design shown on each variation. For example - on white t-shirt we should choose dark design and so on.

We don't have much technical knowledge, so we hope that you could understand our needs and propose a solution.
We are looking forward to answering all your questions regarding this description.
Specific technologies required: PHP
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