You need to make sure that the devel packages for the given template are installed so yum is available to the iworx-cp installer. Alternately you can use the iworx-cp templates at http://updates.interworx.com/iworx/vps/virtuozzo/ instead of the default vz ones.
I uploaded the 188MB file via VZCC > hardware node > application templates > upload new template. It took forever. However, I do not see it in the list now.
It’s an OS template not an app template. Just login to the main node (the server itself, not a VPS instance) and RPM install it. You then need to do a vzpkgcache <name of template> and it will show up in the VZ interface.