How Can I Use Group Policy to Manage and Enforce Application Settings for Third Party Web Browsers

I manage the network for a school district and utilize Group Policy Extensively to manage configuration settings for staff and students alike.  We like the benefit of locking down Internet Explorer so that the settings we want get delivered.  The problem is that we are now utilizing several browser based cloud applications that don't support IE.  The vendors of these applications recommend Chrome and Firefox.  The problem of course is that now that we have made those web browsers available to users, a large number of our users are utilizing those browsers exclusively.  Since I don't know a way to enforce settings for those browsers, it makes our network susceptible to the Internet.  Surely someone out there has this same problem I of managing configuration settings for multiple browsers.  Can someone give me some guidance and direction on this?