Managing VMs for application deployment.

Hey linuxadmin, I have a question about KVM / QEMU and how you would manage those VMs.

We currently have a single server deployed with some PHP applications. These are deployed with Capistrano.

We have another app that has conflicting requirements (ie: needs apache instead of nginx etc).

I think the easiest way to deploy this application would be to create a VM.

As a bit of background, I'm a programmer by trade but I've taught myself a lot of dev ops / sys admin stuff. I'm comfortable using Vagrant and Ansible to setup vm's for development but I have not used Ansible or Puppet to manage VM's for deployment.

Do you guys have some best practices for this area? Do you manage the VM's youself and run your playbooks / chef scripts on that?

I'm also confused as to what technology is used. Is KVM a backend to QEMU? (Note: free would be the best option, I don't think we can shell out for vmware or anything).