all the distros here are outdated or broken and very difficult to find -> http://www.psdevwiki.com/ps3/Distributions

If you want a usable ps3 distro use Red Ribbon Linux

Also here's a guide which shows you how to downgrade to 3.55 from any CFW.
Installing any one of the CFWs from the download link above will automatically prepare your internal drive.
In order to install the rogero 3.55 CFW you will need to turn on system debug update under the qa-flag menu and then install the CFW in safe/recovery mode.