You don't need a smart turbo for zwift - either an ant + power meter or a garmin speed / cadence sensor so that it can work out your virtual power. You also need an ant + dongle so that the laptop receives the signal form your power meter / speed / cadence sensor and preferrably an extension usb cable as dropouts can occur when not in range of the dongle. Zwift does not use the power reading from your trainer so a very basic turbo can get you going !