Damn, labview looks neat. Is there any documentation other than the webcasts they have, because you need to fill in a big form just to view the webcasts?
It mentions talking to 'any sensor' and a whole lot of stuff over USB. I have no idea how it does that, though, and without some documentation I wouldn't be able to suggest anything. It sounds proprietary though, and I'm guessing they sell an adapter or something.
Do you already have a sensor that measures flow, or do you need a variable injector driver and a flow sensor to talk back to labview?
Are you implementing a peak-and-hold driver, or just running these injectors saturated?