Automated Purchase Order Flow (n8n or Python)

I’m looking for an automation expert who can help building a forecasting and reorder system that automatically keeps all warehouses and sales channels stocked.

Scope
- Collect inventory & sales data from Amazon (FBA DE, FBA UK, FBM) and JTL (3PL warehouse)
- Forecast demand and calculate reorder points (ROP = daily sales × lead time + safety stock)
- Automatically create and send purchase or production orders (PDF via email) to the OEM
- Track ETAs, inbound shipments, and send alerts for low stock or delays
- Google Sheets dashboard for live monitoring, order logs, and forecasting

Setup
- n8n (preferred) or Python, optionally combined with Google Apps Script

Integrations:
- Amazon API / Flatfile
- JTL API or CSV
- Gmail or SMTP for order emails
- Google Sheets (for tracking & reports)
- Modular structure to easily add new channels (e.g. Shopify)
- Handles both single-level and multi-level BOMs (some kitting at 3PL, some at OEM)

Deliverables
- Fully working automation (forecast → reorder → email)
- Configurable lead times and safety stock
- Google Sheets dashboard or alert system
- Short documentation on how to extend SKUs or channels

Please include:
- Your preferred approach (n8n, Python, or Apps Script hybrid)
- Estimated time & cost
- What data or API access you’ll need

I’m happy to pay more if we build something more solid and scalable together, but please note that payment is only made for working results.
Looking forward to your proposals and ideas!