I have always taught this with Gear Down and about best glide speed. One reason for the gear down is to make sure its down and ready for landing as most teach this as an emergency to a power off 180. Another is it is easier for the student to pick a spot right under the tire (if in a high wing) to use as a reference to remain over. Also, you don't have to listen to the gear warning horn going off the entire maneuver with the throttle idle.
You do have to be careful about the best glide because it does get close to a stall at times.
The DPEs I have talked to like to see the student reach at least a 50* bank at least once every full turn even though the PTS does not specify a bank angle.