E-commerce Store + Amazon Integration

I want to launch a dedicated loja virtual in Portuguese and have every item simultaneously available on Amazon.
The job covers the full technical setup: choosing or configuring the e-commerce platform, creating a coherent storefront with secure checkout, and linking it to an Amazon Seller Central account so stock, pricing, and orders stay in sync.

Key deliverables:
• Fully functional online store (Shopify, WooCommerce, Magento or a similar solution you recommend) ready for customers
• Amazon marketplace account configuration with branded product-listing templates
• Real-time inventory and order-management bridge between the two channels
• Basic walkthrough so I can add future products and run promotions on both fronts

Everything must be responsive, bilingual-ready (PT-BR by default), and optimised for fast loading. Provide an estimated timeline and outline any third-party apps or APIs you plan to use so I can approve them before work starts.