As they produce voice are resource sensitive, you are right. Other problem is the way to install the supported version of Operating System (Cisco 2003.1.2) that you should in VMWare (It would interesting for labs, but haven't found the way in the documentation).
Third problem is support. As that configuration is not supported by Cisco in CCX.
Are you getting this error “Installer User Interface Mode Not Supported. The installer cannot run in this UI mode. To specify the interface mode, use the -i command-line option, followed by the UI mode identifier. The value UI mode identifiers...
The below trick might come handy when you have to add a new node to a cluster but you don't have or is unsure of the security password for the publisher. This procedure has been around for ages.
1) Login into the CLI of the Publisher.