Is installing it locally (like in /home/yourname/local) an option?
1) is not an option--if it's running on the server, it can't read your modules from your pc.
2) you can, but it will take time, and not be as robust as the hardened and proven File::Find module.
You can always look at File::Find's source, but i would strongly recommend using the module itself (are you sure it's not installed already?). If you're going to write it yourself, i'm sure you can find a recursion example of doing just this...
A workaround would be to use unix tools .. construct a commandline w/somthing like (i'm sure you'll want to tweak the egrep settings):
my $cmd = 'find /some/path -name \*.sas | egrep -l ' . "'(" . join('
+|',@words) . ")'";