Deployment support: Integrating is not the end of the world. Even after integration, you may need support. There can be lots of problems with the new software. For the smooth functioning of your organization, you need the help of people who can provide deployment support.
Customer reviews: The customer is the king. A good consultant will have satisfied customers. Go out in the market. Look who is having a good reputation among the crowd. Choose only the market leader in this domain.