You don't need to have a directory script that works with Wordpress. Just install a directory script in a sub-folder and add a link to it from the blog. You might put a link in the blogroll, add a link in the footer.php, or edit your header.php to get one to show under your blog's banner logo, or even make a small banner for it and put it on the sidebar using html in your widget text function.

I use the free version of the qlWeb directory. http://www.qlweb.com/downloads/qlWebDS_Free_3.1.0a.zip You can see it in action at my http://videotubedirectory.com website.

This one is available in 4 versions featuring additional abilities as you move up the $ ladder ... and you can compare features here: http://www.qlweb.com/modules.php?name=qlWebDS_Features

I personally like having the script notify me of new submissions so I don't have to check it manually everyday, and I see he has it in the $9.95 version... hmmm, I might just be doing some upgrades!

Anyway -- do post about what solution you end up using and how it's working for you.