Cheers, with the directory of directories, the only thing i can suggest is that you keep in mind quality.

There are directories and there is crap, dropped domains acting as some high PR domain, scam bid directories, scam gen directories, just plain crap MFA supposed directory sites and the list goes on.

If you want people to take your list serious and attract people to the site then the more work and effort you put into providing the best resource the better.

Load it with crap and it will drag your site down with it.