i use simplescreenrecorder which is really decent for my use!
it does not have support for using your webcam as a facecam though but everything else is really easy to use with little overhead!
To get support for mp4 and mp3 you need to run this
which will replace libavformat53 and also install libmp3lame0
sudo apt-get install libavformat-extra-53 libmp3lame0
it would also not be a bad idea to install ffmpeg too!
PS: the image on the persons homepage is old, the newest version uses pulse