Shopify Extension similar to teepublic

General information for the business: We sell a range of funny garments that are made to order
Description of requirements/functionality: We design a range of funny slogans and graphics for t-shirts, hoodies, sweatshirt etc etc that are made to order.

We would like a site similar to teepublic.com but is based on the shopify platform.

Our aim is so that we can easily upload our designs and they are then overlayed onto each type of garment.

We would like some additional features, whereas teepublic only allows you to upload 1 colour design, for each type of design we may have 2. For example we may have a black design which would go on a white/light coloured garments, but a white style design that would go on black coloured garments.

An SKU for each variation must be created automatically created in the form of [Design Abbreviation]-[Shortcode for garment]-Size-Colour
For example for a design called "Eat Sleep Fish Repeat" on a large mens blue t-shirt it would be ESFR-MTS-L-BLUE

As we also sell on eBay & Amazon there must be a title automatically created. So design with have a separate attribute for the eBay Title and Amazon Title. This should be part automatically generated e.g. Eat Sleep Fish Repeat Mens T-Shirt [Additionally keywords we can add on the submit page]

Each type of garment that is created must go into a category; Mens > T-Shirt or Mens > Sweatshirt, or Mens > Hoodie. However on the website we want users to be able to browse by the type of design e.g. Funny or TV Shows or Movies etc.
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