Would it be possible to still have a syndicated ad network, but that it would feed you articles in some structured format, that you would get on your backend, and then insert as articles into your blog/website? This way you could format them any way you want.
Of course the payment model would have to shift from displays to something like overall performance of the ads (by scanning outbound clicks and associating them with purchases) and pay by month. And some policing in order to avoid stuff like getting the ad from the network and never actually displaying it.