Maybe a local CPAN mirror could help? You could update the mirror only when you really want updates (instead of updating daily or hourly). Then, point all cpan(m) instances to the local mirror.

Or, if all servers and dev machines use the same OS, build an OS-specific package (*.deb, *.rpm, whatever ...) with the required modules, and use the OS to install and update the packages from a local package repository.

Alexander