Towards privacy, longevity, and independence, the private cloud would ideally be located in a distributed fashion on our own local hardware, i.e. no colocation or rackspace/aws. We would use open source cloud management/provisioning tools. But, allow flexibility and varied hardware and hypervisor (within reason) architecture/vendor selection if possible without sacrificing inter-hypervisor HA/Failover/Sharing of CPU/Memory/Storage.