Wordpress membership/paysite script

A friend asked me to help her set up a membership pay site where she can post photos and possibly videos while charging users a recurring monthly membership fee. It is adult content, therefor needs to work with one of the adult payment processors - We've not chosen a specific one yet. I'm pretty sure I want to use Wordpress as it provides a good base for a single user blog with an administrative interface she'll be able to use easily, but I'm open to other options (such as joomla or drupal). I found a couple plugins, but none support a payment processor that'll handle adult content. While I'm a developer by trade, as this is a favor I'm not really looking to invest a month or more of free time to roll my own. Anyone know of any free or moderately priced scripts?

Thanks for your time and help!

TLDR; Looking for wordpress membership/paysit script for single user adult content blog.