ScreenFlow has proven to be good so far, but has also caused us to lose important content due to corruption and some times simply not working.
Check out ambrosia's software, it's worth buying. For audio I love Wire Tap Studio: http://www.ambrosiasw.com/utilities/wiretap/. WireTap records the 'internal audio' of your computer, and you can isolate programs ex: chrome or iTunes. It also let's you control the recording format (file type), bit, sampling, etc.
I have not tested their video capture software but if it is anything like WireTap it will be great!