If you have virtual servers you could always create a separate prefix for the webapp. Then you compile and install perl into the prefix. You can usually get better performance from compiling your own perl (ie without threads.) Another plus is you don't have to worry about upgrading the system perl harming your webapp.
You could then tarball up the whole thing and not worry about the "crust" and "filling". Or make the whole "crust" from scratch on the next machine and only tarball the filling... your Catalyst app. This takes a little longer to compile everything but is very straightforward and like I said you have less to worry about in the future.
I think this is analogous to what CountZero and Your Mother have said. I like compiling perl as well because XS modules (ie Class::MOP) won't break on a major system perl upgrade.