I need a scope

I am investigating moving away from our existing web design bureau. I will need a full redesign and believe that our current suppliers are not up to the job. What i want now is to understand how I will need o build out the scope of what we want to communicate to a web designer front end and back end.. I have a multi-site golf club business in Holland and I will need transactional functionality and multi-lingual capability. What information do we need to prepare in order for somebody to design us the best website in the industry including navigation, simplicity, and uniqueness?