I suggest you search this forum Blair as the best methodology has been covered here many times. The winning formula is to convert to ProRes via Compressor, fixing frame rate and audio sample rate issues at the same time.
AIC is an old and not very good codec which has been far and away superseded by ProRes. If you don’t change sample rate and frame rate from the 5D you will be sorry.
Hard drives are so fast and cheap that there is no reason to transcode to 720 AIC from 1080 H264.