What are you editing your Videos on? I can recommend a program that has multiple timelines and can PIP, Like Pinnacle Studio. But to run that Program or most mid range editing Programs, you need a Desktop Computer, with a good Graphics Card and a Surround Sound Audio Card, these two latter are a cards that are extra components that fit into the expansion ports of your computer’s motherboard. The Program can run on an off the shelf laptop, but the moment you press render, that cheap laptop will lock up and be unusable for anything for a couple of hours while the computer runs at 100% for the time it need to process the video.
http://www.pinnaclesys.com/
