Futuristic AI-Powered 3D Grocery Web Application

I need a futuristic AI-powered 3D shopping website/web app.

Concept:
When users open the website, they enter a 3D desi-style grocery/karyana shop environment. A realistic AI shopkeeper/avatar wearing shalwar kameez should be sitting inside the shop. Users can talk to the AI shopkeeper by voice or text, ask for products, and the AI should recommend/search items and add selected products to cart.

Important features:
1. 3D virtual store experience similar to a game
2. AI human-like shopkeeper/avatar with voice/text chat
3. User can say things like “mujhe chai, sugar, rice aur cooking oil chahiye”
4. AI should understand the request, search products, show options, and add items to cart
5. Product search should connect with Amazon API / Amazon affiliate product data
6. Cart system with quantity, price, product image, and checkout button
7. Checkout should redirect users to Amazon product/cart/affiliate checkout where possible
8. Admin panel to manage categories, featured items, prompts, banners, and AI behavior
9. Mobile responsive design
10. Fast loading and clean UI

Tech preference:
- Frontend: React / Next.js
- 3D: Three.js / React Three Fiber / Unity WebGL if better
- AI: OpenAI API or similar LLM
- Voice: speech-to-text and text-to-speech
- Backend: Node.js / Python
- Database: PostgreSQL / MongoDB
- Amazon integration: Amazon Product Advertising API or latest Amazon Creators/API-compatible solution

Important note:
Please first confirm what is technically possible with Amazon API, because Amazon may not allow direct checkout inside our website. If direct checkout is not allowed, use Amazon affiliate product links and redirect users to Amazon for final purchase.

Deliverables:
- Full working website
- 3D shop scene
- AI shopkeeper chat system
- Amazon product search integration
- Cart and checkout/redirect flow
- Admin dashboard
- Source code
- Deployment on VPS/Vercel
- Documentation
- 30 days bug support

Please share:
1. Your suggested tech stack
2. Similar 3D/AI projects you have built
3. Timeline
4. Total cost
5. How you will handle Amazon API limitations