Have a stop here and take a tour through out the resources section.
Be sure that your team has agreed on the criteria for decision making. This can be a formal worksheet or an informal bulleted list with weights.Personal Connection & Trust
At the end of the day, when buying professional services, you are buying people. Do NOT short change this aspect of the decision. If you are uncomfortable with the people from the beginning, it's only going to get worse. Choose people with whom you feel you can have a comfortable, professional relationship. You do not want a new best friend, but chemistry is critical.