You can try contacting Boonton directly. I have spoken with them in the past, and apparently they have different samples of LabVIEW code that can be used with some of their instruments. These are not complete drivers, but should still help you get started programming your instrument (assuming they have what you are looking for). I attempted to get Boonton to contribute their LabVIEW code to the Instrument Driver Network, but had no luck. Maybe you can mention that to them when you talk to them.
Jason Hobbs
Instrument Drivers