Convince the developers of fantastico that the script (the free version of course) is comparable in terms of popularity with other scripts that they autoinstall (http://www.netenberg.com/fantastico_scripts.php
), offer to help them iron out any kinks they might face in the process of integrating it in their offer, and anything else they might require. Once you're in the Fantastico list, you'll have the script at the fingertips of probably 90% of cPanel users.
Or try to convince Installatron (Fantastico's competition) to add it to their list, and use that as an argument to get into Fantastico as well.
It would appear that these autoinstaller developers tend to prefer software that have certain licenses though (GPL and the like), or maybe it's these applications that more easily become popular enough to become a blip on their radar?