E-Commerce Website Development for Plumbing Supplies

I am looking for an experienced web developer or agency to build a modern, responsive e-commerce website for a plumbing supplies store.

Project Requirements

The website must include:

A professional and user-friendly design.
Product catalog with categories and search functionality.
Full online store with shopping cart and secure checkout.
Integration with Portuguese payment methods:
MB WAY
Multibanco Reference
Real-time stock management.
Product availability displayed on the website.
Customer account area with order history.
Order management system.
Contact form and company information pages.
SEO-friendly structure.
Mobile-friendly (responsive) design.
Administration Panel

The store owner must have full control over the website through an easy-to-use admin panel, including:

Add, edit and delete products.
Manage categories.
Update product prices.
Upload product images.
Manage stock quantities.
View and manage customer orders.
Update order statuses.
Manage promotional banners and featured products.
Generate basic sales reports.
Preferred Technologies

I am open to suggestions, but I would prefer a solution based on:

WordPress + WooCommerce
or
Shopify
or
A custom-built solution if it offers significant advantages.
Deliverables
Fully functional website.
Secure payment integration.
Responsive design.
Easy-to-use administration panel.
Basic documentation explaining how to manage products and stock.
Deployment on my hosting server.

Please include examples of similar e-commerce projects you have completed, your estimated delivery time, and the total project cost.