The only way to replace cios60 is to do it yourself, so don't do that. You could do it with dop-mii, Multi-Mod Manager, darkcorp uninstaller, pimp my wii, and others. Don't muck up your system ios or system menu.
You can always install the system ios and system menu of your desire, but I don't support 4.2, 4.3, and probably nothing else in the future. 4.1 is it, that is where everyone should be and stay. I doubt any future updates to the SM will bring any advantage, if it does I will rework the method, but I doubt that will ever happen.