I came across another stockings affiliate program and I did a search of the forums to make sure it hasn't been mentioned before. It's actually a group of sites through:
My Sexy Legs:
http://www.msle.co.uk/
Affiliate sign-up page:
http://www.msle.co.uk/pages/affiliate.php
And again, I'm not affiliated with them in any way but thought I'd pass them along to other who promote the stockings niche.
Jessica