it's not the training company, it's the instructor that matters.
Anyway, if I were you, I would not invest in a training too much. UCCX (and contact centers) are an not an easy topic and they cannot be explained in detail during a 5 day course. I believe it would be better to hire an experienced engineer and have him show you around (both installing and configuring the system). The initial cost might be a bit higher but I think it would be money well spent.
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.