I am in the market for a CRM solution for a small business (1-5 users) - looking for advice on which CRM will best suit the needs.

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