Looking for a specific theme

Hello everyone,
I am planning a website and looking for the right theme. My site will be a Q&A web site like just answer.com. Much more simpler at the start bu here is the idea, people will ask questions about relationships, their children, problems by a fee and my contracted psychologists, pharmacists, etc.will answer them personally by e mail. Then they will ask 2 or 3 follow up questions.
My question is what kind of theme I should use, what do you recommend.
Thanks for your answers…