Don't confuse PPM and CPAN.pm -- they are similar but different.

IIRC, it's possible to download a specific version of a module from CPAN, but I'm at a loss how at the moment.

If your systems are the same OS, same OS version, same processor type, and everything is compiled with the same compiler then you can indeed usually get by with copying your modules over wholesale. (For pure Perl modules, you can do it even if these criteria aren't met.)

As for where they are, your modules probably live someplace like /usr/lib/perl or /usr/local/lib/perl but I'm not sure where they'll be on a particular system, and it's been a long time since I've touched FreeBSD so I can't even tell you for certain where your OS installation would stick them by default.