Oliver,
You can submit driver requests for these instruments at:
http://zone.ni.com/idnet97.nsf/instrumentdriverrequest/
NI develops instrument drivers based on popularity and instrument availability.
Without an instrument driver, you can communicate with the instrument by sending it the appropriate commands using VISA. The Instrument I/O Assistanat in LabVIEW 7.0 or later can help simplify instrument communication.
Regards,
Hobbs