Try blamads, they have contact locking technology, so the user has to take some action before seeing your content.
I think that should work for your sites
If you generated good traffic, I think contact with Ads Company by email, in email send all details about site and traffic and show your offer, cheap and suitable. You are using ****** that?s great because its income amazing, I have good experience with ******.
I think Content locking is a good option for you. You can also use adsense. But some other ad companies like BLAM, EWA are really cool. I am using them in my blogs and getting good profit.