To rebuild your Shopify theme using React while maintaining full admin functionality, consider using Shopify Hydrogen. It’s Shopify’s recommended React framework for building custom storefronts with full access to Shopify’s backend via the Storefront API.
If you need deeper integration with Shopify’s admin, a Shopify App using Node.js and React might be a better fit. You can use Shopify App Bridge to interact with Shopify’s admin features while handling storefront rendering separately.
For a balance between flexibility and Shopify’s ecosystem, a Hydrogen + Oxygen (Shopify’s hosting solution) setup could be ideal. However, if you want full theme-level access, you may need to work with Liquid + React (using Alpine.js or Vue for interactivity) instead