12.4(6)XW would be required for the newer phones as it also allow you to configure display lighting timeouts.
Regarding phone FW, it's a bit of a gamble to get it right. Try with the latest available in any case. For user locale, you need to use 7941 files, renaming them to the names used by the 7945 (debug tftp events will show you which names are these).
I saw a CME 4.1 download which included phone loads for the new phones. I would probably suggest this might solve your problem - I will be trying it on one installation soon as I have ordered some of the same phone.
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.