Build a WordPress site with a database and payment functionality

Description

I'm looking for an experienced WordPress, WordPress plug-in, eCommerce website designer for a ground up website' which is estimated be a 3-6 month project working primarily with me. This is a B2C / B2B print on-demand website, including paintings, photography, prints and digital art. There will be thousands of artwork choices and therefore thousands of thumbnail images in various galleries for the customer to browse through starting with the drop down menus. Some images might fall into various categories. For example a bright orange beach sunset would be found in multiple drop downs; sun, beach, water and orange to name a few. As a working photographer, I work with several local printers in my area. One of my print vendors introduced me to the company they use - MyOrderDesk which creates web to print storefront solutions. I have had several conversations with them about how an online on-demand order logistically travels from website to the print vendor. The question I have is how does a product like MyOrderDesk effect and integrate into the building of the WordPress site?