Build a web database that can use feeds to compare pricing on items

This project will be in two phases.
For the first one, I am looking to create a web database that I can put feeds from different stores and will be able to group similar products together, allowing one to price search and find the cheapest/similar products from those feeds.

Similar to google shopping. This would need to be compatible with the most common eCommerce platforms such as Shopify, Magento, WooCommerce, Square, Bigcommerce, and some others.

The second aspect of the project will be a comparison chrome plugin. Basically, when you will go to Amazon or a few other websites, this plugin will search the database and pop up other websites that are selling the same/similar products.

In order to bid on this project, please mention the word “cat” so I know you read the full description, also, please post links to similar work that you have completed in the past.

Thank you