Hi mdanjou,
The USB-6008 device is supported by the DAQmx Base driver, which is a subset of the DAQmx driver. The DAQ Assistant is a feature of the DAQmx driver not supported by the DAQmxBase driver, hence the reason you're not able to use the USB-6008 with it. Since you're able to acquire data from the NI Data Logger, you already have the DAQmx Base driver installed. A variety of LabVIEW examples have been included with the driver, which you can use as a starting point and to evaluate LabVIEW for your application. You can find the example from:
Start (Windows) >> Programs >> National Instruments >> NI-DAQmx Base >> Examples >> LabVIEW 7.0
Hope this helps!
Regards,
Lesley Y.