Some good tools to take a look at if you haven't already are ManageIQ and OVirt.
ManageIQ according to its FAQ, is a "cloud management platform (CMP) that adds additional capabilities to your existing virtualization, private cloud, and hybrid cloud infrastructure. ManageIQ provides scaleable self-service interfaces, provisions virtual system images, enables metering and billing, and provides workload optimization through established policies."
OVirt according to its about page, is a "virtualization management application. That means that you can use the oVirt management interface ( the oVirt engine) to manage hardware nodes, storage and network resources, and to deploy and monitor virtual machines running in your data center. If you are familiar with VMware products, it is conceptually similar to vSphere. oVirt serves as the bedrock for Red Hat's Enterprise Virtualization product, and is the 'upstream' project where new features are developed in advance of their inclusion in that supported product offering."
Both of these are sponsored by RedHat, and ManageIQ is at a higher level where it is managing existing virtualization providers, while OVirt is more of a virtualization provider, although it has a management UI.