Have you looked into using any scripting tools to help you accomplish this? You can use VMware vSphere PowerCLI to schedule these clones and delete the clone if it already exists or potentially name each clone something different. You'll need some knowledge of PowerShell scripting but there are many resources available to you on the Internet.
PowerCLI can be downloaded here: http://www.vmware.com/support/developer/windowstoolkit/
What about using VMware Converter to schedule V2V conversions? Have you considered that? I'm not sure if it gets around the problem of having the clone exist already but it is probably worth looking into.
Matt | http://www.thelowercasew.com | @mattliebowitz