Question
My "sales funnel" is wide at the bottom (1000s of companies), and narrow at the top (looking for 1 company). Overall sales cycle is ~2 years. Criteria important to me include - ease of use, reasonably priced (<$100/user/month), good lead management, performance tracking, email campaigns/integration, customizability, and collaboration capabilities
Answer
For one to five users you might try Hubspot or see the cool ways people have used Airtable as a CRM.