Trying to find one quick release plate that works well with completely different camera types is a useless quest in my opinion.
If you were using EOS cameras for still photography and a lightweight consumer-type video camera, I would suggest that the Manfrotto RC2 quick release system would work just fine. However, if you are considering a significantly larger video camera, then a different type of tripod mount (one with the support pin arrangement like the 501PL has) would make more sense for the video camera. That QR plate, however, would be a royal pain in the posterior on most EOS cameras and lenses.
My suggestion is that you first show us what sort of still equipment and video equipment you intend to use. Then, we can help suggest some practical solutions for you. The best solution might be different heads for each purpose, though both could be used on the same tripod legs.