Qualified prospects

I work with several small companies that needs qualified leads. I am investigating a partnership with someone that can do that function for a number of companies. So the resource I am looking for is a person that can funnel interested customers into a funnel and qualify them in the process for the company to convert into a sale. So I assume that it requires skills and knowledge of marketing the different products to prospective customers and through an effective funneling process provide qualified leads for sales to persue. The idea to pay per qualified lead is the service required.