Custom Freight Zone Enhancement in Shopify

Our store has a section dedicated to oversized items, but the current freight zone setup isn't as professional as we would like. I'm looking for a Shopify expert who can help me enhance the freight zone for these items.

Specifically, I'm looking for:
- A way to not be able to ship some products out of some regions like here -- https://www.ttplastics.co.nz/products/30-000litre-water-tank
- Improved display of shipping options in a more professional manner

My current shipping rate calculation method for oversized items is a flat rate based on weight. This needs to be factored in when improving the freight zone.

Additionally, I would like the new freight zone feature to automatically adjust shipping rates based on:
- Customer's location
- Item dimensions

Ideal skills and experience for this job include:
- Proficiency in Shopify and its shipping zone features
- Knowledge of setting up accurate shipping rates and options
- Prior experience in customizing freight zones for oversized items
- Good communication skills to ensure a professional display of shipping options

Looking forward to working together on enhancing the freight zone for our oversized items.