Contact xxx affiliate programs (for paysites), and tell them that you would like to use their clips. They should be able to give you access to their paysites for free, and you could download the newest (and not only) videos from there. Then edit, it, and use only 9:00 minute videos or so (this is what http://beeg.com is doing, I think).
As far as placing ads on your website, I would recommend the following ones:
Exoclick
Plugrush
Ero Advertising