The contemporary literature on cloud resource allocation is mostly focused on studying the interactions between customers and cloud managers. Nevertheless, the recent growth in the customers' demands and the emergence of private cloud providers (CPs) entice the cloud managers to rent extra resources from the CPs so as to handle their backlogged tasks and attract more customers. This also makes studying the interactions between the cloud managers and the CPs essential. In this paper, we investigate both of the mentioned interactions. For the interactions between customers and cloud managers, we adopt the options-based sequential auctions (OBSAs) to the cloud resource allocation paradigm. As compared to existing works, our framework can handle customers with heterogeneous demands, provide truthfulness as the dominant strategy, enjoy a simple winner determination, and preclude the delayed entrance issue. We also provide the performance analysis of the OBSAs, which is among the first in literature. For the interactions between cloud managers and CPs, we propose an auction-based scheme for resource gathering. Through incorporating the offered prices, we capture the heterogeneous desires of the CPs in leasing their resources. We conduct a comprehensive mathematical analysis of the two markets and identify the bidding strategy of the cloud managers.