I have extensive experience with trademarks and have handled portfolios for multinational corporations. For $5, I will use the search tools at my disposal to search for any name or slogan you are interested in trademarking. I will let you know whether the name is available as well as give you a list of all the similar names and slogans that turn up (if any exist). I will not only do the search for you, but also provide detailed information on the whole process.
*Detailed information only applies to U.S. searches as each country will have their own set of rules and regulations. International searches will strictly be the search results.