Need an expert level Shopify developer to make a custom made theme exactly same as our existing site

Need an expert-level Shopify developer to make a custom-made theme exactly the same as our existing site.
Our existing website: https://respirationnation.com/
It's a simple website that just needs to be implemented into Shopify.
Pages content, testimonials, Slider, and product details can be managed easily from the admin panel.

Some important features need to be integrated
1. Related product showing like G3 machine page will show G3 parts & accessories
2. Affirm payment gateway integration, already installed the app just need to add Prequalify now to the product pages

Example:
https://www.oxygenplusmedical.com/products/reconditioned-respironics-simplygo-oxygen-concentrator-1

3. Popup window to collect Name, phone, email, and address when someone new entering into the website.

Here is my Shopify site
https://respirationnation.myshopify.com/

You need to start the theme development from scratch because the existing Shopify theme coding is crap.
Delete/remove all themes and apps, so you can make them from scratch.

Will allocate more projects if the guy is suitable and excellent in Shopify development.

Thanks for your bidding !!