Cloud computing is having a great impact on the evolving IT enterprise today. It provides on demand services with pay-as-you-go manner. Service consumers struggle traversing through an array of cloud service providers with the different design and management of all the transactions payments, selection of appropriate service providers etc. A solution to this problem is the usage of cloud service brokerage. Cloud brokers acts as an intermediary between the cloud service providers and consumers. In this paper, the authors discuss the evolution of Cloud Service Broker (CSB) and propose a model within a CSB for the selection of service provider, by forming a cluster of similar service providers.