Well with some kinda of modification the script can do anything you want. I am not quite sure what you mean by 'growing into dark or light type' though. I do recommend you to play around with the script for a while and see what it can do for you at this point. Of course you will need some coding if you want a highly customized site.
This is an old adoptables site I used to develop, which was based on an old version of this script that is no longer supported. I no longer work on it nowadays, but it does illustrates that it's totally possible to build an awesome pokemon site out of it:
http://www.pokemansion.net/index.php