It is possible - however quite a few changes have to be made within templates and scripts etc.
Essentially you need to remove the colour and the Moderator icon for posts made by moderators, yet keep it for admins.
You also will need to adjust the ability for moderators to show who edited the posts (but you may not wish to allow anonymous edits all the time - or change it to 'A moderator edited post'), there are also areas such as the members list.
Therefore it is not really possible to list all the changes needed in a simple reply. It would really be a mod, so you might wish to request this over at ubbdev.
If it was a one line change, I would be more than willing, but this is too complex for my time at the moment.
Sorry about that.
