I'm with Anonystude. Call them 'Brize' or whoever, and see what response you get.
In my experience, though, I agree that only Brize seems to have the LARS provider called 'Radar' because they also have 'Zone' for transits. Everyone else combines the positions.
Just to add to the confusion... operating into or out of one of these airfields you may well end up using Zone as Approach because Approach is only on UHF... Benson seem to have a number of frequencies they can play swapsies with so they can provide Director and Talkdown on UHF or VHF, for example. (I'm glad they do, or it would be no IAPs for me...!)
Tim