I appreciate what you are trying to do but as a student I was consistently frustrated by peer presentations because I felt the quality of my education suffered. Likewise, while I'd be thrilled if somebody presented me with a high-quality video that would help improve my education, I would resent paying tuition to sit in a classroom and watch a recording that I could be watching from the comfort of my home in my off-hours. We attend school to learn material and context yes, but also for the experience and dialog of getting to ask questions to a world expert. That is what makes the education more valuable than reading a book. I am sad that you have chosen this as an element of your solution. However, if you publish that video or others online, please give us a link to it, it sounds wonderful.
Having students do individual research projects and then presenting can also be very hard on the students because one badly done presentation, if the material is never retaught, can create gaps in a student's education. This is particularly difficult for classes which are part of a sequence, where this lack of knowledge will impact a later class. You are creating work for yourself too, as the lectures which you teach which build upon these principles will frequently have to be adjusted to cover material which was not adequately expressed, and make it harder for you to recycle and perfect your slides.
Additionally, students in classes based on rotating presentations tend to specialize in what they presented. This gives them an unusual advantage on the test: the optimally localized behavior for a class on a curve is to learn the material, convey as little as possible while making the class feel well-informed, and then ace it on the test, thus lowering the curve. If you do insist on doing this, you should have the class' average success on the exam reflect in some way on the presenters.
This is the solution that I know http://news.ycombinator.com/item?id=2774695 I posted it on your website as well. I respect your desire to not have your class be fearful of you. Perhaps you could trade with another professor: you address his cheaters and he addresses yours.