Shopify Catalog Enhancement

I need a Shopify expert to enhance our catalog features for better functionality and user experience.

Key Features to Implement:
- Users should be able to select quantities and add items directly to the cart from catalog search results.
- Product prices should be displayed within the catalog search results.
- Sort categorized search results alphabetically by category title (A-Z).

Technical Requirements:
- Must be compatible with existing Shopify and external catalog system integration.
- Ensure seamless user experience on mobile devices with the new features.

Design Guidelines:
- I have specific design guidelines that need to be followed.

Please reference and test the website: https://mightyspares.com.au
Test the catalog by selecting vehicle details or going to: Search By Car > Rego > 'YCT01Y' / NSW > Search

Ideal Skills and Experience:
- Proven experience with Shopify development
- Strong understanding of mobile UX/UI
- Ability to integrate with external catalog systems
- Adherence to specific design guidelines

Looking forward to your proposals!