Create a full page in Shopify to match our existing site

I need a developer that can create a full working page linked to our products/stock page where clients can select from a large number of sweets selections totalling to a particular amount then linked to checkout.
This site will give you an idea of what we require.

https://youpickwemix.com/products/picknmix?variant=34482292817964&currency=GBP&utm_medium=product_sync&utm_source=google&utm_content=sag_organic&utm_campaign=sag_organic&gad_source=1&gclid=Cj0KCQjwwMqvBhCtARIsAIXsZpZ0fF5N7IQWoE8ESk5lW9nh-ksK4fc2nFZuMIvlpGoG0VYLqhGSX-kaAlrREALw_wcB

and this site


https://www.thesweetstore.co.uk/products/1000g-pick-mix-mini-pouch-20-fillings?variant=33835023007879&gad_source=1&gclid=Cj0KCQjwwMqvBhCtARIsAIXsZpYY3erw-p4xIHlB9LQ6Fvh7K9Y4fUmfJr8OAmsB1WRjA7g7WBTf7vIaAoXOEALw_wcB


We must be able to add and remove items easily as they come in or out of stock.

We will also need a pop up which we can easily modify on an on going basis.

Our current website is candydrops.co.uk

Our store is live so your work must be fully tested before deployment

Thank you