I still haven't confirmed with 100% certainty that there is a 3rd party app that will do exactly what I am looking for.
You know, I still have the original Droid but can't help following this thread. I want to see this work for you. If I were in your shoes, I would first look at the built-in profiles utility on the 'Pro and see what they can and cannot accomplish. Besides the predefined profiles you can create custom profiles. Then I would look at apps such as Tasker, Locale, Setting Profiles, Timeriffic.
One or more of these in combination might give you what you need. I'm fairly confident you can get this done though it will take some research and effort. The only issue I see is being able to silence individual gmail accounts rather than all or none. Tasker is the most powerful of the profile type apps, there is a thread for it on this forum and tasker has it's own wiki too.