To put in my .02 cents, I have found the RedHat distributions to be a fairly easy install process, and they are in sync with CPAN for the latest version of Perl. I installed RedHat 7.0 sometime back, after it first came out, and it had Perl 5.6.0 as part of the initial install. I have also heard some good things about OpenBSD as well, especially the install process which is very easy.