Build a Custom AI Sales Research Agent (Clay.com Alternative)

I am looking for an expert Python/AI Developer to build a custom "Research & Enrichment" tool similar to Claygent (from Clay.com). The goal is to automate the finding and deep researching of 10,000+ e-commerce companies based on specific criteria.
Key Requirements & Workflow:
Lead Sourcing: The agent should search for e-commerce brands in the USA, UK, and EU (using Google Search API/Serper.dev or BuiltWith API) based on specific niches.
Qualification Filters:
Identify if the store is on Shopify.
Estimate if they have a minimum of 30-50 orders per day (using traffic data/social engagement).
Deep Research (The "Agentic" part):
Scrape the website (using Firecrawl or Jina Reader) to find Total SKU Count.
Identify Sourcing location (China vs. Local) by reading Shipping/About Us pages.
Determine the e-commerce platform and current tech stack.
Waterfall Enrichment:
Set up a multi-step email finding logic: If Apollo API fails, try Hunter.io, then Prospeo/Proxycurl (LinkedIn scraping).
Verify emails using ZeroBounce or MillionVerifier.
Output: Sync all data into a Google Sheet or a PostgreSQL Database.
Preferred Tech Stack:
Language: Python
Framework: LangChain / LangGraph or CrewAI (Agentic Frameworks)
LLM: GPT-4o / Claude 3.5 Sonnet
Scraping: Firecrawl / Browserbase
Search: Serper.dev / Tavily AI
Deliverables:
A functional script or backend that can process batches of 500-1000 leads at a time.
Dashboard or simple UI to trigger searches and download CSVs.
Documentation on how to rotate API keys and manage costs.
Please share your experience with AI Agents and Web Scraping at scale when applying.