As others have pointed out, any language that you are comforatable with is the one to use. Using perl is definitely possible, however. Openair.com is a commercial PSA that does most of what you are talking about, and it is written exclusively in perl (disclosure: I worked there for a couple years). Perl is a very good web language (preaching to the choir) for any web application, even business ones. I believe Amazon is also a perl shop.
Be aware that what you are talking about is no small task, take a look at OA and realize that it is the fruit of two+ years work.
-jackdied
