Hello,
I have read your description and I can help you on the Shopify store with -
Online Shopify store/website includes a lot of categories and sub-categories and sub-sub-categories than items, each item has a unique code number and image with some values like (colour, size, surface finish, other info and availability).
The sign-up/login option for regular people is basic and contractors need to be created only after proof from the owner and they will get 10, 20 or 30% off on general products.
Search bar: Customer needs to be able to search between items with the name or code and shows some suggestions like a google search bar for example.
Side-Page filters, so customer can minimize the search by (size/Color/product/availability/etc).
An easy and flexible way to add more categories and products. (You will be adding only 2-3 product in each category - As there are a lot of items I'll add them myself)
Photo gallery for each product which communicates with price, size and colour for each piece.
Daily Backup - Security - payments options and delivery.
I have 7 years of PHP, Mysql, Java, Wordpress, Flutter, Python experience, contact me for detailed discussion.
Regards,
Abby