The developing countries can leverage the potential provided by cloud computing to leapfrog from poorly equipped to ICT enabled nations if the widely known issues related to power supply, limited communication infrastructures, security and privacy usually experienced by the ICT field in the developing countries are addressed. Lightweight cloud computing can address these issues but requires i) enhanced service brokerage to efficiently share the limited resources of the lightweight cloud infrastructure by managing and monitoring inflow of requests from customers and mapping these requests to virtual machines and cloud infrastructures and ii) a reliable database management system capable of keeping and updating the track of customer's requests and cloud infrastructure status. This paper presents a novel data model for cloud services brokerage that supports the allocation, control and management of virtual system based on brokering function between cloud service providers (CSPs) and cloud users by integrating and managing cloud resources in a heterogeneous cloud environment. The model is implemented for a private lightweight cloud network using a graph model in an OpenStack environment. The experimental results show that a graph model has better performance than a relational model in term of queries execution time.