You only need flash prep for anything below 4.5.
Quote from Emu support page.
"EOS 4.0 through 4.10 users need to load Ultra Prep to enable your sampler to read compressed files. EOS 4.5 users need only to install the new version of EOS 4.6 (flashprep not required). "
Sounds like you only need the 4.61 disk.
I am upgrading to an Ultra next week, just wondered why you are rolling back to 4.61?
4.7 was one of the main reasons for me getting an Ultra, so a little prewarning of any headaches would be handy.(Realtime resonance and FAT support)