Why invite trouble?

White flies are hard to control. You have to spray continually. I'd say no to that opportunity.

I'd refuse that plant.

To answer your question, whiteflies are more of a disaster like scale. If you try to spray them they simply fly off elsewhere only to return. Systemics are useful in control, but not not a treatment I'd start indoors in November as your other plants would be at risk from the whiteflies and the systemics wouldn't do you any favors either. As stated above, refuse it.

tj