It looks like sdlperl.org is under construction, and at SDL's libs page I did not see SDL_perl. So, if you want to build from source a bit of googling for sdl perl or something similar might turn up a source tarball.
For a package
this site has a few sdl libs(+sdl_perl 1.2). I think all tgz's there are also avail on linuxpackages.net, which can be 'swaret'-ed upon.
-notaslacker