Calling companies to identify the right decision maker

We produce lists of companies, which will be exhibiting in tradeshows taking place in the middle-east and/or in Europe. We know the general address and phone numbers for each of those companies, but need you to identify the name of the decision maker (optionally: his title and direct phone/email address) in charge of building their stands/booths (could be a PR or a marketing person, etc.). There might be several calls necessary for one company. 3 questions: 1. What would be your business model? 2. How much would you charge? 3. How long would it take to call 300 companies (assuming there are 2 calls per company)?