Need editorial log system to track edits

For an EE2 MSM network of websites I need to set up an editorial log system to track edits by Contributors, who have limited permissions to create, edit and publish specific items such as news and events. All that is really needed is to have a log of entry edits with the following information, all from the entry:

User name
Site or entry url
EE entry name and number
Time/date (not just of creation but of edit)
entry status (Open/Closed)
Comments field for issues or notes (could this be a Notepad comment since these are specific to an entry?) 

Ideally this would add to to a log and generate an email notification of the action edit to Editorial.

Any thoughts on how to do this? Many thanks in advance!

Gregg