Yes, 5.8.8 is current. As for where to get it, that depends on what you want to run it on. You can build it yourself, from source, but if you don't have the complete kit (as I would guess you don't from the fact that you don't seem to have perl already) then it's more work to get all the prerequisites to build it than to download and install an RPM.
Since you say you want an RPM, I have to guess that you are running (most likely) on RedHat or SUSE. Either way, the most straightforward way to get Perl is by using your package manager, uptodate, yum or yast, depending on what distro you are using. If you don't know about package managers, you could tell us what distro you are running and we could probably help.
This question might be better asked in the Linux/Unix/BSD forum since it isn't really about Perl as such.
Best Regards,
Paul