I have an ezine, but it's not large enough (yet) to draw the kind of response you need. There are a few ezine publisher partnerships that you can use to advertise to all their combined subscribers (278,000 subscribers.
http://www.wheredomomsgo.com/user/SDTopening.html
http://www.mywizardads.com/index.php?pubID=PSplitt
Ezine Blaze allows you to send ads, articles or anything you like to their 13000 (so far, 1000's added daily) members (most members are ezine publishers!)
http://www.ezineblaze.com/index.php?15700
I submit all my articles to this service and I know a lot of big time ezine publishers go to it for their daily articles (LOGON for one).
http://www.MakingProfit.com
Hope that helps!