NI USB-6008 can acquire real and imaginary values from UniWest 454 via its analog outputs.

Here is how to setup NI USB-6008 to combine those two analog channels and make a complex pair value.

Physical wiring:

This example uses differential input mode.
Wire Analog H from UniWest 454 to analog terminal position 2 and 3 of NI USB-6008. (Core wire to position 2 and shield to position 3)
Wire Analog V from UniWest 454 to analog terminal position 5 and 6 of NI USB-6008. (Core wire to position 5 and shield to position 6)

InspectionWare configuration:

In the channel properties, set Complex to True.
New properties will be added, namely Channel (Re) and Channel (Im).
Put 0 for Channel (Re)
Put 1 for Channel (Im)

Note that this is on demand data collection(at a nominal rate of 1kS/s), use Clocked Scan to get the maximum sampling rate (10kS/s) NI USB-6008 offers.