if you still want this done, you can contact me by email (address in profile). I recently made an ad system that can display animated gifs and other images, either on the right sidebar at a location you choose, or within the newsfeed (mixed in w/ posts basically). It also lets you specify html within your ad and some other stuff that isn't present in the official OssnAds feature. in either case, you can set it to randomly select an ad, and in the latter case, you can specify how often you want it to repeat (for example, once every 3 posts). It could be extended to allow videos without too much trouble.