Automatically redirecting certain users to a particular viewer in a single Essentials Site

I am finding myself in a peculiar scenario.  But I’m guessing others out there may have had the same request.  

 

My management team has asked me to make one of my Sites visible to outside consultants and Contractors (which contains sensitive infrastructure information) for viewing & querying purposes only.  They wish to have the downloading and exporting capabilities taken away.  I was thinking that developing an additional viewer in this Site would be the way to go.  

 

The vision is to have these outside users be automatically redirected to this alternate Viewer within my Site when they log in to the Site.  For this, I imagine they would have to be part of a Windows Integrated – Windows Group within my Active Directory and set them up as a Group in my permissions for this Site.  Also, I envision that when these secure users log out, they would be redirected automatically to the “default” (public) version of this Site.  This way, I can control the context menus they have access to (no download or exporting of data), but not have to require them to use a different URL to access the Site.  

 

I thought this could be done by setting Viewer permissions in my Site, but I have since learned that only Mobile App Framework uses these Viewer permissions, they do not control whether a user can launch an HTML 5 Viewer in a browser.  Further, I am not sure on how to automatically re-direct certain users to certain viewers within a particular Site.

 

My question: is my vision stated above possible? If it cannot be done out of the box, is a workflow my only method of accomplishing this?  

 

An insight would be greatly appreciated.  I would really rather prefer not to have to give out separate URLs to different groups of users.  

 

Thanks!