E-Commerce Website Build

I need a complete e-commerce site built from the ground up. The goal is a professional online store that is secure, responsive, and easy for me to manage once it is live. While I have not committed to a specific platform yet, I am comfortable choosing whichever solution you recommend (Shopify, WooCommerce, Magento, or another option) as long as it suits the scope and future scalability of the shop.

Key deliverables:
• Modern, mobile-responsive storefront and product catalogue
• Smooth cart and checkout flow with major payment gateways integrated
• Order management dashboard, automated email confirmations, and basic tax/shipping rules
• SEO-friendly structure, SSL setup, and performance optimisation
• Brief hand-off session showing me how to add products and track orders

Please outline your proposed platform, timeline, and any past e-commerce examples you think match what I’m after.